Will musicians ever be replaced by robots?

A Quora user asks whether artificial intelligence will ever replace human musicians. TL;DR No.

David Cope and Emily

If music composition and improvisation could be expressed as algorithmic rule sets, then human musicians would have reason for concern. Fortunately, music can’t be completely systematized, much as some music theorists would like to believe it can be. Music is not an internally consistent logical system like math or physics. It’s an evolved set of mostly arbitrary patterns of memes. This should be no surprise; music emerges from our consciousness, and our consciousness is an evolved system, not an algorithmic one. We can do algorithmic reasoning if we work really hard at it, but our minds are pretty chaotic and unpredictable, and it isn’t our strong suit. It’s a good thing, too; we may not be so hot at performing algorithms, but we’re good at inventing new possible ones. Computers are great at performing algorithms, but are lousy at inventing new ones. Continue reading

Panel on games in education

I contributed a chapter to a soon-to-be-released book, Learning, Education and Games (Volume One): Curricular and Design Considerations. I wrote about the potential value of video games  in music education. The book will be out in October 2014. Here’s the table of contents.

Learning, Education and Games (Volume One): Curricular and Design Considerations

We’re having a launch party on October 9th at the NYU Game Center, with a panel on games, featuring the contributors to the series. In addition to myself, the panelists will include Elena Bertozzi and Gabriela Richard. The book’s editor, Karen Schrier, will be moderating.

Update: here’s a drawing of Elena, Gabriela, Karen and myself by Jay Boucher.

Games in Education panel by Jay Boucher

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Shared sample projects

My students at NYU and Montclair State are beginning to venture into producing their own tracks. There are two challenges facing them, the small one and the big one. The small challenge is learning3 the tools: remembering where the menus are and which key you hold down to turn the mouse pointer into a pencil, learning to conceive of notes and beats as rectangles on the piano roll, troubleshooting when you play notes on the MIDI keyboard and no sound comes out. The big challenge is option paralysis. Even a lightweight tool like GarageBand comes with a staggeringly large collection of software instruments, loops and effects, even before you start dealing with recording your own sounds. Where do you even begin?

The solution I’m using with my classes is the shared-sample project. Students are challenged to build a track out of a particular sound, or set of sounds. The easy version requires that they use the given sound, along with any additional sounds they see fit to include. The hard version, and for me the really interesting one, requires that they use the given sound(s) and absolutely nothing else. I was inspired in creating these assignments by the many Disquiet Junto shared sample projects I’ve had the pleasure of participating in. I’m trying out my own project ideas on MSU advanced audio production independent studiers Dan Bui and Matt Skouras, and will soon be giving shared-sample projects to my beginner-level classes as well.

The first assignment I gave Dan and Matt was to use eight GarageBand factory loops to build a track. They were free to do whatever processing they wanted, but they could not use other sounds. Also, they only had an hour to put their tracks together. Here are the loops:

Eight loops

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Electronic music tasting menu

Right now I’m teaching music technology to a lot of classical musicians. I came up outside the classical pipeline, and am always surprised to be reminded how insulated these folks are from the rest of the culture. I was asked today for some electronic music recommendations by a guy who basically never listens to any of it, and I expect I’ll be asked that many more times in this job. So I put together this playlist. It’s not a complete, thorough, or representative sampling of anything; it mostly reflects my own tastes. In more or less chronological order:

Delia Derbyshire

This lady did cooler stuff with tape recorders than most of us are doing with computers. See her in action. Here’s a proto-techno beat she made in 1971.

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Music theory blues

I’m reading a lot Schenkerian analyses of blues right now in service of my forthcoming article about blues tonality. Each paper I read is wronger than the last. On the one hand, they fill me with righteous rage, but on the other hand, that rage does at least help me focus my arguments. Here are some particularly awful quotes from a scholar who will remain nameless, because I don’t believe that the racism is intended:

Blue notes, by nature, are alienated from their harmonic environment and have a dissonant relationship with them, giving the blues and all its derivatives a rough, angry character. Nevertheless, the hostility of blue notes toward the surrounding world may be mitigated—“domesticated”—through consonantization.

Blue notes (BNs), by nature, spoil the diatonicism of and cause dissonance in “clean” chords. But these notes may achieve their own independent harmonization, thereby being domesticated and turning into “environment-friendly” consonant notes.

The products of the consonantization of the BNs, which appear in a major-mode harmonic environment, are necessarily flatted degrees. These degrees turn the BNs from minor notes, which are “alien” to the major chords that build the basic harmonic progression, into “family” notes that are “at home” in these chords. The legitimacy that the flatted chords give the BNs is ostensibly the opposite of the “emancipation”that Arnold Schoenberg gave dissonant notes when he freed them from having to resolve to consonance, since the BNs by nature are dissonant notes with no obligation to be resolved.

However, the domestication of the BNs is an emancipatory act, since they thereby stop clashing with the harmony and instead become settled in it.

In Example 1(e), we see flatted or “minorized” degrees, among them VI and III. These degrees now include 3ˆ and 7ˆ not as BNs but in a mixtural framework—that is, as an insertion of flatted notes in a major key. Both of these—mixture and BNs—are common in the Beatles’ songs. Are they related? Ostensibly, they are two completely different things: the journey back in time in quest of the origins of blues will take us to the Mississippi Delta and from there to Africa, whereas the search for the origins of mixture, which is anchored in traditional harmony, will eventually lead us to eighteenth- and nineteenth-century Europe. The connection goes through the “domestication of BNs”—when it can be shown that a particular BN has changed from being outside the consonant harmony, in which case we may regard it as a garnish or a “disturbance,”to being an integral part of a consonant triad. If, for example, we can claim in a particular context that the III chord in Example 1(e) is based on a BN (G), then the status of this BN has improved substantially relative to its status in (c): instead of being an outsider, it becomes a distinguished member of the club of the flatted mediant without losing its blues character.

The status of these [blue] notes in the harmonic society improves substantially in part B: they become the roots of VII and III, and thus they become respected members of the community and live in consonant harmony with the rest of the notes. Their past is nevertheless evident in the descriptive term CBN, which is imprinted on their identity cards.

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Blues tonality

Most Americans who study music formally do so using common-practice era western tonal theory. Tonal theory is very useful in understanding the music of western Europe in the eighteenth and early nineteenth centuries, and the music derived from it. However, tonal theory is inadequate to explain the blues and other musics of the African diaspora. Given the central role of this music in both popular culture and art music, music theory classes do their students a grave disservice by not discussing its harmonic content.

The blues cannot be explained by Western tonal theory. Nevertheless, the blues emerged in western culture and is now a central pillar of it. McClary (2001) observes that while twentieth-century music has no single main stream, it does have a “mighty river” that follows a channel cut the blues:

When LeRoi Jones published his powerful book Blues People in 1963, his title referred to the African American musicians who fashioned the blues out of their particular historical conditions and experiences. Yet a music scholar of a future time might well look back on the musical landscape of the 1900 s and label us all “blues people”: those who inhabited a period dominated by blues and its countless progeny (32-33).

It no longer makes sense to think of the blues, or any other music of the African diaspora, as non-Western. Therefore, Western music theory must grow to accommodate the blues, the same way that the music itself has.

The blues is based around a very different set of harmonic expectations than the ones underlying classical music. In the blues, major and minor tonality are freely intermingled. Dominant seventh chords can function as tonics. Tritones need not resolve. The blues scale is as basic in this context as the major scale is in tonal harmony. In conventional tonal theory teaching, the major scale is taught as the most basic and fundamental theoretical building block. The very language of tonal theory proceeds from the assumption that the major scale is the most ‘natural’ one. For example, in the key of C major, we modify the ‘natural’ seventh B to produce the ‘flat’ seventh B♭. In the context of western European music, this convention makes good musical sense. But western Europe is not the only salient influence on Western musical culture. The music of the African diaspora is equally fundamental, and it has come to weigh increasingly heavily over time.

African diasporic musical culture expresses itself through all of America’s indigenous music: jazz, rock, hip-hop, R&B, country, and of course, the blues. The music academy gathers all of these genres together under the term ‘popular music’ (with the exception of jazz, which in recent decades has become a ‘legitimate’ art music.) Feld (1988) goes so far as to describe American popular music as “a euphemism for Afro-American popular musics” (31). Growing up in America’s popular culture enculturates us with a quite different sense of what ‘natural’ harmony is. For example, DeClerq and Temperley (2011) show that the♭VII chord is vastly more prevalent in rock melodies than in common-practice classical music. To a lifelong rock listener, B♭ may well sound more ‘natural’ in the key of C than B♮ does.

I propose that we teach blues tonality as a distinct category from major or minor, combining elements of both with elements not found in either. Furthermore, I propose that we present blues tonality as being as fundamental a tonal category as major or minor, rather than as a strange exception. Popular musicians, who tend to be self-taught, already effectively do treat blues this way (Green 2002, 43). Some jazz theorists do as well; Jaffe (2011) divides jazz harmony into three distinct tonal systems: diatonic harmony as described by tonal theory, modal harmony, and blues. Given how pervasive the influence of jazz and rock are in all other Western music, it is time for the music academy to address blues as part of standard theory pedagogy.

Defining blues tonality

There is no widely agreed-upon precise definition of blues or blues tonality. I will argue that blues tonality consists of a scale, the blues scale, accompanied by characteristic microtonal blue notes in between the scale tones. Blues harmony comprises chords whose roots are blues scale notes, but whose other constituent pitches may be drawn from the entire chromatic scale.

The blues scale

As a first step to understanding blues tonality, we need to define the blues scale. There are several scales referred to as ‘blues scales,’ but the one most often described is comprised of the intervals:

  • minor third
  • whole step
  • half step
  • half step
  • minor third
  • whole step

The C blues scale would therefore be the pitches C, E♭, F, F♯, G, and B♭.

Blues scale

This definition of the blues scale is used by Levine (1995), Harrison (2001), Terefenko (2014), and Jaffe (2011). However, Jaffe adds the caveat that the blues scale is a less a cleanly defined scale in the usual sense, and more a pedagogical convenience. Some authors describe two distinct blues scale, a ‘major’ and ‘minor’ blues scale. Jaffe (2011) defines the “Major Blues scale” as the sixth mode of the standard (minor) blues scale. The C major blues scale would be C, D, E♭, E, G, and A—the sixth mode of the A blues scale (35). Greenblatt (2005) and Terefenko (2014) use the same definitions of the minor and major blues scales.

Blues is a tonality, not a song form

Blues as a musical idiom is often equated with the twelve-bar strophic form that shares its name. It is important to distinguish between blues tonality and the blues song form. The twelve-bar blues form is what Stoia (2013) describes as a ‘scheme’—a preexisting harmonic ground or melodic structure that forms the basis for the creation of songs. Songs using the twelve-bar scheme need not be in the blues genre at all. For example, “Shuckin’ The Corn” by Flatt and Scruggs (1957) and the theme song the 1960s Batman television show both use the twelve-bar scheme, but neither one could be mistaken for blues. Meanwhile, a great many blues tunes use different song forms from the twelve-bar scheme. Jaffe (2011) cites “Work Song” by Nat Adderley and Oscar Brown Jr (1960) and “Moanin’” by Bobby Timmons (1958) as fitting this category. Aretha Franklin applies blues tonality and phrasing to nearly everything she sings; I would argue that in so doing, any material she delivers becomes blues.

Is the blues scale dissonant?

Western music theorists frequently characterize blues melodies as being dissonant against diatonic harmony. Given the hegemony of European-descended music theory in the academy, this is unsurprising. As McClary (2001) observes, “blues musicians privilege a vast palette of sounds that European-trained ears tend to hear as distorted or out of tune” (35). For example, Everett (2004) refers to the tritones and half-steps characteristic of blues as “intrinsically dissonant” (17).

Wagner (2003), like Everett, sees the blues as occupying the major-key system, and the blues scale as violating the rules of that system. (Like many authors, she uses ‘blue notes’ to refer to blues scale notes, not to the microtonal pitches discussed below.)

Blue notes, by nature, are alienated from their harmonic environment and have a dissonant relationship with them, giving the blues and all its derivatives a rough, angry character. Nevertheless, the hostility of blue notes toward the surrounding world may be mitigated—“domesticated”—through consonantization (353).

Wagner describes blues scale notes as “spoiling” the diatonicism of “clean” chords. By reharmonizing blues scale notes with chords from parallel minor, they become “family” notes that are “at home” in their chords, thus giving them “legitimacy” (354). Reharmonizing a blues scale note “improves” its status because “instead of being an outsider, it becomes a distinguished member of the club” (355). Reharmonized blues scale notes are transformed into “respected members of the community,” although their African roots remain “imprinted on their identity cards” (356). Why use such judgmental language, and why use expressions so closely associated with the oppression of ethnic and racial minorities? We need not suspect Wagner of harboring any racist sentiments, but her choice of language reveals an implicit cultural bias widespread in the music academy.

Tymoczko (2011) analyzes blues as part of jazz use of dissonance, including “polytonality, sidestepping and ‘playing out’” (374). In his view, blues is the beginning of jazz musicians’ willful violation of tonal rules, part of a larger practice of intentional asynchrony between melody and underlying harmony.

The origins of [harmonic asynchrony] can perhaps be traced to the blues, which is characterized by ‘blue notes’ that create a delicious dissonance with the underlying harmony… The music thus suggests a kind  of polytonality, or clash between independent harmonic streams, in which an upper-register (African-American) ‘blues scale’ contrasts with a lower-register European harmony (374).

Tymoczko immediately follows his discussion of blues with the example of jazz improviser Wayne Marsh playing an E major chord over E♭ major tonality. However, this analysis misses an essential distinction: while jazz sideslipping is indeed experienced by most listeners as dissonant, blues is heard as consonant, possessed of its own harmonic logic. For all of its violations of western tonal theory, blues is in no way atonal. There is always a strong tonal center, recurring at the beginning of every chorus. Indeed, a great deal of blues music never departs from the tonic. Given that blues has a clear internal logic organized around a tonal center, we need to ask what the nature of that tonal logic is.

Stoia (2010) regards the blues scale as essentially dissonant, in conflict with the underlying diatonic harmony. He acknowledges, however, that this dissonance does not have the same expressive effect that it does in European-descended music. While blues melodies fall outside of the diatonic system, they do not create the feeling of unease or conflict that they would in a classical context. Stoia, like other theorists, uses the term ‘dissonance’ as being coextensive with ‘notes outside the European tonal system.’ However, in a blues context, blue notes sound perfectly ‘correct’ and ‘natural.’ Rather than viewing blues as a violation of diatonic norms, we need to understand it as a parallel rule set of norms in its own right. These norms can be surprising for classically-trained musicians. Weisethaunet (2001) points out that in blues, the minor third can sound more correct than the major third over a major chord.

Blues players will also employ the major third in their solos and phrases; however, if this is overdone, it will take the feeling away from that of the blues and make the music sound more ‘jazzy’ or ‘country-like’. From the perspective of the blues performer and listener, the major third against the major chord may thus sound more ‘dissonant’ than the application of the minor third over the major chord (105)!

Jaffe (2011) distinguishes the standard blues from ‘major blues’ tonality, which includes both ♭3^ and 3^. He would presumably concur that major blues sounds more like jazz than  blues per se.

For all of its violations of western tonal theory, blues is in no way atonal. There is always a strong tonal center, recurring at the beginning of every chorus. A great deal of blues music never departs from the tonal center. The one-chord blues is practiced by musicians as diverse as John Lee Hooker and John Coltrane. For example, Hooker’s 1967 recording of “I’m Bad Like Jesse James” never moves from its tonic, E. The blending of major and minor that characterizes blues is especially clear here: the piano chords are minor, while the guitar chords are dominant.

Given that blues has a clear internal logic organized around a tonal center, we need to ask what the nature of that tonal logic is.

Is blues really a form of modal mixture?

Since the blues freely combines elements of diatonic major and minor tonality, it could be understood as a kind of modal mixture; for this reason, van der Merwe (1992) characterizes blues as a “modality,” not a tonality (118). Turek and McCarthy (2013) see blues as arising from the adding of the flat seventh to diatonic chords:

The lowered seventh present above each root imparts a dominant seventh quality to each chord. The blues and its offspring are the only Western vernacular music in which the Mm7 is routinely divorced from its function as a dominant in need of resolution (584).

Therefore, major blues is really a type of modal mixture, borrowing elements of parallel minor. In this understanding, minor blues is coextensive with diatonic minor, aside from the addition of #4^ the only point of harmonic “friction” (594).

Tagg (2009) sees blues not as the importing of minor mode materials into major tonality, but the reverse. He locates blues tonality partially in the practice of substituting a major triad for the tonic chord in diatonic minor or Dorian mode. He argues that the chords characteristic of blues can be derived by simply placing a major triad on every root of those modes. Such harmonic parallelism has its roots in many African cultures, and is a natural fit for guitarists, especially those who play with slides in open tunings. The parallel major triads are implicit in rock’s power chords, because the third is present in the overtone series, which is frequently augmented by distortion.

There is less of a need to define a distinct ‘minor blues tonality,’ since minor-key blues has merged in modern practice with minor modality generally, to the point of the two being coextensive. John Coltrane’s “Equinox” (1960) is a classic example of minor-key blues.

It uses the characteristic minor blues subdominant, ♭VI7, which is comprised “almost exclusively” of the minor blues scale notes (Jaffe 2011, 37), and can be used in any major or minor-key tune to impart blues feel.

Blue notes

If the blues scale is a disputed term, the blue note is even more so. Non-specialists frequently and incorrectly refer to the flatted third and seventh (and sometimes the raised fourth) in the blues scale as blue notes. These pitches should be referred to as blues scale notes. Blue notes are microtonal pitches that lie between the piano keys. Many theorists confusingly use the term ‘blue notes’ both for microtones and piano-key notes. Turek and McCarthy (2013) describe blue notes both as as the equal-tempered♭3^ and ♭7^, and later, as “pitches, most notably the third and seventh scale degrees, slightly flatter than their equal-tempered counterparts” (593).

The most commonly referred-to microtonal blue note is the neutral third, the pitch lying mid-way between ♭3^ and 3^. Stoia (2013) is one of many theorists who describe the ‘blue third‘ as being either minor or neutral. Van der Merwe (1992) goes further and asserts that “[i]nstead of the major and minor thirds of the printed page, most of the thirds will be neutral in actual performance” (123). Elsewhere he notes that the third is not the only note to be treated this way; several pitches can be flattened by a quarter tone or a full semitone.
“The degrees of the mode treated in this way are, in order of frequency, the third, seventh, fifth, and sixth” (119).

Blues musicians treat pitches “as mobile, unstable units instead of treating them as discrete points in a scale” (Tallmadge 1984, 155). Should we consider blue notes to be stable units, of equal significance to the blues scale itself? Or are they best thought of as embellishments, the consequences of blues musicians’ pitch play? In one view, blue notes have an intrinsic instability analogous to harmonic dissonance: “So close is the parallel that it is not misleading to use the term ‘melodic dissonance’” (van der Merwe 1992, 120).

By contrast, Titon (1977) incorporates blue notes into his basic definition of the blues scale, and places them at the heart of his understanding of blues tonality. Using a corpus of recordings of “downhome” or country blues made between 1926 and 1930, Titon defines the set of the most commonly occurring pitches as the ‘downhome blues scale’ (155). The downhome blues scale in C consists of the following pitches:

  • C
  • D
  • E complex (E♭, E, and two distinct intermediate pitches)
  • F
  • G complex (F#, G and one distinct intermediate pitch)
  • A
  • B complex (B♭, B and one distinct intermediate pitch)
  • C’
  • D’
  • E’ complex

Titon believes that the scale should span a tenth rather than an octave, because the blues musicians in his study treat the lower octave differently than the higher one. He identifies this practice as the basis for the bluesy sound of the 7#9 chord, with major third in the lower octave and the minor third on top. Titon also tallies the most frequent movements from one blues scale pitch to another within his corpus, and proposes a generative system for blues melodies by cataloging melodic contours derived from them.

Weisethaunet (2001) sees blue notes as a central component of blues tonality, but is reluctant to define them strictly. In his view, the pitch play that produces blue notes can not be meaningfully separated from the rest of the musical devices that make up blues feel.

[I]n blues performance every note may be bent or altered, but in different ways depending on style and how such notes appear in the harmonic texture. One of the most frequently heard ‘blue notes’ as regards pitch discrepancy in post-war electric guitar playing may be that of the bent fourth: this is commonly bent to include different pitches between the fourth and the fifth (and higher pitches as well). The second (which does not even appear in what scholars have named the blues scale) also seems to be a very common ‘blue note’ feature of most blues guitarists’ repertoires: moving between the second and the minor third in innumerable ways. In fact every note of the twelve-tone chromatic scale may appear in a blues tune, possibly also as ‘blue notes’, because microtonality, attack, and timbre variation are such essential parts of blues expression (Weisethaunet 2001, 101).

Perhaps, then, we should take the view that the blues scale is more than a straightforward set of equal-tempered piano-key notes; rather, that it is a group of islands in the midst of the pitch continuum, home bases from which to explore the surrounding microtones.

Blues harmony

Chords in diatonic harmony are generated by permuting notes in the scale. Diatonic harmony is a ‘closed’ system—the chords in the key of C major are all derived exclusively from the pitches in the C major scale. Blues harmony, by contrast, is an ‘open’ system. While the blues scale is frequently the basis for the roots of the chords in blues music, other pitches can come from parallel major, natural minor, Dorian mode, or anywhere else. The chords most characteristic to blues can be built on the roots of the blues scale. The specific quality of those chords is somewhat open for debate, however. I consider the characteristic chords associated with the C blues scale to be:

  • C7♯9
  • E♭7
  • F7
  • F♯dim7
  • G7♯9
  • B♭7

I am least certain of the qualities of the ♭III and ♭VII chords. Those might also plausibly be defined as major seventh chords. The dominant quality is more ‘bluesy’ to my ears, but an empirical survey of blues music could well show that major sevenths are used more frequently.

There are several diminished chords commonly used in blues tonality beyond the ♯IVdim7. A ubiquitous turnaround/embellishment figure uses I7/iii, ♭IIIdim7, IIdim7, I7, or those same chords in the reverse order. Furthermore, the pitches in Idim7 are highly idiomatic to blues melodies. Should these diminished chords be considered fundamental to blues tonality? If so, how should we incorporate them? I do not have a clear answer.

The two most significant differences between blues harmony and diatonic harmony are the 1) blues tonality’s ambiguity between major and minor discussed previously, and 2) the role of tritones, particularly within dominant seventh chords. Both Stoia (2010) and Everett (2004) draw a connection between the flat seventh in blues chords and the flat seventh in the diatonic V7 chord, an ‘embellishment’ that increases the chord’s dissonance and creates an expectation of resolution. Stoia in particular bolsters his case by citing the frequently-used blues device of treating I7 as V7/IV in anticipation of the fifth bar of a twelve-bar blues form. However, dominant seventh chords are not necessarily dissonant or unstable in a blues context. Blues songs routinely begin and end on I7, with a feeling of resolution that is as satisfying as a perfect authentic cadence is in classical music.

While blues musicians use chords, there is not a sense of inevitable progression the way there is in Western classical. Indeed, the dominant V chord is frequently absent in rural blues (Kubik 2005, 207). Rural blues musicians’ implicit rejection of the V-I cadence was made explicit by bebop musicians in the 1940s. While their source material of Tin Pan Alley songs was full of cadences, musicians like Charlie Parker and Dizzy Gillespie disguised and obscured these cadences by means of the tritone substitution and other reharmonization techniques.

Everett (2004) is one of many scholars who describe blues as a mixture of diatonic harmony and minor pentatonic melody.

[T]he blues has an essentially major-mode structure. In the twelve-bar-based “School Days,” Chuck Berry’s vocal and lead guitar parts are thoroughly pentatonic, but the structure-expressing bass and piano boogie in the major mode. The rarity of exceptions, as found in B. B. King’s minor-mode “The Thrill is Gone,” proves the rule. If this seems out of line with prevailing descriptions, which typically rely on reference to a “blues scale” and don’t seem to discriminate between tonal characteristics of melody and backing, consider the rhythm section’s accompaniment aside from all vocal and solo melodic lines. It is in the supportive major-mode instrumental chordal backing, not in the soloistic melodic material, that structural harmony is expressed ([16]).

Everett (2004) asserts that while particular blues songs may not use structural dominants, there is nevertheless an implicit understanding that the dominant functions as it does in diatonic music because “it is of structural value in the major system that is inhabited by that blues” ([18]). This argument would be valid if all blues songs really did make reference to diatonic harmony, but a great many do not. There is an entire subgenre of so-called ‘primitive’ blues songs that have no chord progressions whatsoever. For example, “Spoonful” by Willie Dixon (1960) consists entirely of riffs over a static tonic chord. Whatever this song’s base tonality is, it is most certainly not major.

Contrary to Everett, it is possible for a wide variety of chord progressions to possess a strong blues feel. For example, while Charles Mingus’ “Goodbye Pork Pie Hat” (1959) uses the F blues scale for most of its melody, its chords are drawn from the entire chromatic scale.

Aside from a continually reasserted tonic, blues harmony may not be functional at all in a traditionally Western sense.

In blues harmonic practice, unresolved tritones can appear over any root, sometimes generating an impetus for motion and sometimes not. A one-chord blues can be based on a seventh chord over a repeating bass figure, and can easily accommodate extensions beyond the seventh. The addition of the sharp ninth merely adds colour to the tonic in this case, rather than a tension requiring resolution (van der Bliek 2007, 346).

That said, blues chord progressions are not random. While they may not lead to one another with the inevitability of classical harmonies, they are more satisfying in some combinations and sequences than others.

The issue of functionality within blues harmony is complicated by the fact that, unlike any other scale in common Western use, the blues scale is a kind of universal harmonic solvent. It sounds correct over any chord in any tune (Levine 1995, 230). While the combination of the scale against the chords in a typical blues or pop song produces a great deal of dissonance, in the blues context the dissonance is perfectly acceptable. The clash of adjacent chromatic pitches in blues sounds right, not wrong. Perhaps the best way to understand blues harmony will be to conduct a statistical study of chord progressions across a wide corpus of blues recordings.

Blues harmony in context

The diagram below shows my understanding of how blues tonality fits into the broader western harmonic universe. Following the diagram is an explanation of my terms.

Blues tonality

Diatonic major

This is the major scale and its associated harmony as described by conventional tonal theory.

Diatonic minor

Diatonic minor consists of the natural and harmonic minor scales and their associated harmony.

The supermode

The supermode is the union of the major and natural minor scales. This collection of pitches comprise the ones most commonly used in rock and pop melodies, as determined by DeClerq and Temperley (2011), who also coined the term.

Non-western modes, drones, and pentatonics

There are three major harmonic practices that western musicians have incorporated from the rest of the world, all of which are important to the blues.

  • Modes. Exotic scales have infiltrated western pop through vectors as diverse as the globetrotting dance music scene, big-eared hip-hop producers, rock and metal musicians looking to break out of cliches, film score composers, and  waves of immigrants. Jazz musicians were exploring the major scale modes back in the 1950s, and a wide variety of non-western scales in the 1960s. Pop eventually followed suit.
    e variety of non-western scales in the 1960s. Pop eventually followed suit.
  • Drones. Drones seem very exotic, more a feature of Indian or middle eastern music than blues. However, a huge swath of western pop uses static harmony based on a pedal point, and a pedal point could be considered to be a rhythmically broken drone.
  • Pentatonics. Almost every world culture uses pentatonic scales. Western musicians learn them early because they are easy to play. On the keyboard, playing on the black keys only gives you the F♯ major and E♭ minor pentatonic scales. On the guitar, pentatonics are by far the easiest scales to play.

Jazz major

Contemporary music rarely confines itself to the strict rules of tonal theory. Particularly in jazz, major-key music is frequently enriched with non-diatonic pitches, like ♯4 and ♭7. Levine (1995) and many other jazz pedagogues describe the ‘bebop major scale’ as the major scale with the added ♭6. The ‘bebop dominant scale’ is the mixolydian mode with an added ♮7. (See also Baker 1988.)  I refer to this collection of expanded major scales as ‘jazz major.’

Jazz minor

I use the term jazz minor to refer to the union of all of the different minor scales commonly used in contemporary music: natural, harmonic and melodic minor, plus Dorian and Phrygian modes. Weisethaunet (2001) observes that contemporary blues players will commonly use the Dorian mode against dominant seventh chords, and that the second and sixth scale degrees are common additions to the blues scale generally.

Roots of blues tonality

Where do the blues scale and its accompanying tonality come from? We may never have a single unambiguous answer, but there are several plausible theories. Conventional wisdom says that the rhythms of African-American music descend from Africa, while the harmonies descend from Europe. This oversimplification neglects the African harmonic practices persistent in American music that depart widely from European norms.

Tagg (2009) is one of many authors who explain the blues scale as an extension of the minor pentatonic scale. Harrison (2001) posits that the blues scale descends from the minor pentatonic scale by adding a chromatic ‘connector’ between 4^ and 5^ (35). Jaffe (2011) understands the blues scale as deriving from the flattened diatonic 3^, 5^ and 7^—in blues, these pitches can either replace or coexist with their diatonic counterparts. Characteristic jazz sonorities like 7#9 emerge out of superimposition of blues scale notes onto the diatonic I, IV and V chords (37).

A more complex explanation from the blues scale can be found in van der Merwe’s concept of the African-descended ‘ladder of thirds’ (1992). By this theory, the blues scale originated by stacking minor thirds. Adding a minor third to the tonic gives the blues scale’s ♭3^, and adding another gives #4^. Adding a minor third on top of the major triad gives the blues  scale’s ♭7^.  In blues, ♭3^ resolves down to tonic in the same way that the leading tone resolves to tonic in classical— van der Merwe terms this a ‘dropping’ third. Similarly, 6^ can resolve up to tonic—a ’hanging’ third. The blues’ characteristic ambiguity between major and relative minor creates ambiguity as to where the tonic is. If we regard blues as a form of relative minor, we might consider the ‘tonic’ to be ♭3^, and adding a minor third to it gives the blues scale’s #4^.

Kubik (2005) sees blues and jazz as the effort of black musicians to recreate blues tonality on instruments designed for tonal music. In turn, he locates the roots of blues tonality in several African harmonic practices: the ‘span’ process (a kind of harmonic parallelism), the use of equiheptatonic scales, and tuning systems derived from the natural overtone series. Kubik has observed that listeners to certain field recordings from various regions in Africa find them to be particularly ‘bluesy,’ and that those recordings share particular musical properties.

I discovered that in many cases, the impression was created by just a few traits that appeared in those musical styles in various combinations and configurations: (a) music with an ever-present drone (bourdon), (b) intervals that included minor thirds and semitones, (c) a sorrowful, wailing song style, and (d) ornamental intonation. Songs with a prominent minor seventh in a pentato hexatonic framework also sometimes received this designation, as did pieces that featured instrumental play with a clash between a major and minor third or with a specific vocal style (Kukik 2005, 191-192).

African practice is not the only plausible root for the blues scale. Various European folk musics, particularly those of the United Kingdom, also contain both blue thirds and blue sevenths, as well as the ladder of thirds. It is possible that the myriad African musical practices surviving in the United States were pruned down to what we know as the blues due to the “catalytic influence” of British folk styles over the course of the 19th century (van der Merwe 1992, 145).

Examples of blues tonality

John Lee Hooker (1967) – “I’m Bad Like Jesse James
Like Dixon’s “Spoonful,” Hooker’s song is a one-chord blues that never departs from the tonic E. The blending of major and minor that characterizes blues is especially clear here: the pianist plays minor chords, while Hooker’s guitar chords are dominant.

Jimi Hendrix (1967) – “Purple Haze
The song is centered around the famous ‘Hendrix chord,’ otherwise known as E7#9. The other two primary chords are G and A7, both with roots from the E blues scale. There are additional chords under the guitar solo, but these function as a modal backdrop to blues tonality.

Parliament (1975) – “P. Funk (Wants To Get Funked Up)
Like many funk songs, this one mixes all of the minor scales with the blues scale over a harmonically static background.

Michael Jackson (1979) – “Don’t Stop ‘Til You Get Enough
This tune is largely in B mixolydian mode, but its keyboard solo uses blues tonality. An even stronger blues connotation comes in the first interval of the vocal melody, 3^ dropping a tritone to ♭7^. Every line of the verses begins with this tritone, and its prominence gives the song a bluesy edge. In 1979, Michael Jackson was beginning the process of bridging the racial divide in American pop, a process that would culminate in the unprecedented crossover success of Thriller. His most popular albums struggled to reconcile ‘black’ and ‘white’ music (Roberts 2011, 29).

Janet Jackson (1986) – “What Have You Done For Me Lately
Here is another example of freely mixed major and minor. The line “What have you done for me lately” is minor, and “ooo-ooo-ooo-oooh yeah” is major. The keyboard line that repeats throughout the choruses spells out a diminished chord, a stack of minor thirds that further reinforces the blues feel.

Blues tonality and genre

Good popular musicians intuitively understand how much blues tonality to use in order to sound more characteristically ‘jazzy’ or ‘country’ or ‘rock.’ Along with rhythm and timbre, blues content can be a significant help in delineating the often overlapping and vaguely defined genres of American vernacular music. Funk harmony, for example, is mostly blues and jazz:

Funk

The equivalent diagram for country would be almost the inverse of funk, since it is mostly diatonic with a dash of blues and little to no jazz. Rock is more evenly split between diatonic and blues, with varying amounts of jazz depending on subgenre. Jazz itself blends blues tonality into diatonic showtunes, and diatonic harmony into blues tunes. Western classical music is largely diatonic, aside from twentieth century modernism.

Classical

The most stylistically eclectic musicians will occupy larger harmonic territory. For example, The Beatles’ music encompasses the entire diagram.

Beatles

This diagram does not attempt to harmonically define or classify all of the world’s music. The bottom circle should really be a complex set of overlapping circles describing many different harmonic practices. Nevertheless, for the present purposes, I felt that the simplification was justified.

Blues tonality and rock

Rock operates in a mostly diatonic harmonic universe, but it features characteristic deviations from the conventions of tonal harmony as well. I will argue that these deviations are due to the influence of the blues.

Blues is one of the central pillars of rock. Indeed, a great many rock songs are simply the blues played faster and louder. The first rock song to top Billboard magazine’s main sales and airplay chart, “Rock Around the Clock” by Bill Haley and the Comets (1955), is a straightforward twelve-bar blues (Browne 2001, 358). The blues influence was felt especially strongly by British rock musicians in the 1960s, and they in turn spread awareness of blues to mainstream white American listeners (Schwartz 2007, 22).

Beyond direct borrowing and imitation, how might we gauge the impact of blues on rock? One invaluable resource is DeClerq and Temperley’s corpus analysis of rock harmony (2011). The authors analyze the twenty top-ranked songs from each decade of Rolling Stone magazine’s list of the ‘500 Greatest Songs of All Time’. The Rolling Stone corpus uses a broad stylistic definition of ‘rock’—so broad, indeed, that it includes an assortment of non-rock songs, including representatives from jazz, country, pop, R&B and hip-hop.

The most immediate difference between common-practice harmony and rock harmony as represented by the Rolling Stone corpus is the high incidence of both the ♭7^ scale degree and the♭VII chord. These are rare in common-practice minor mode, and vanishingly rare in common-practice major mode (DeClerq & Temperley 2009). While the flat seventh has entered rock through a number of vectors, like the Mixolydian mode used in many folk musics, blues is likely the main basis for the use of this device.

Rock’s other major departure from common-practice tonality lies in the distribution of pre-tonic and post-tonic chords. In rock, the most common chord preceding the tonic is IV, whereas in common-practice music it is V. Furthermore, in rock, the IV, V and ♭VII chords are as likely to precede the tonic in rock as to follow it.

In light of this data, one might conclude that rock is not governed by rules of ‘progression’ at all; rather, there is simply an overall hierarchy of preference for certain harmonies over others, regardless of context” (DeClerq & Temperley 2009, 61).

Again, rock has many streams of influence, and any number of folk musics have contributed to the relaxation of the rule that V must precede I. Once again, however, blues is likely to have played the strongest role.

Blues tonality is not widely discussed in rock theory, but its presence is often implicit. For example, van der Bliek (2007) describes the dominant seventh sharp nine chord (the ‘Hendrix chord’) as adding a “blues tonal element” (344). The Hendrix chord is built around a set of pitches that represent “a significant portion of the tonal markers of melodic activity in the blues idiom” (van der Bliek 2007, 345). It goes a long way towards defining blues tonality at well.

Blues has also made its presence felt in broader popular music through its use of static, loop-based harmonic structures. If there is a single element unifying all forms of popular music, it is the loop structure, as opposed to the linear narrative structure of classical music. Tagg (2009) observes that chord loops in blues-descended pop create a sense of, states, conditions or ‘places to be’, not as components of a large-scale tonal scheme.

All of the above points notwithstanding, Everett (2004) argues that blues tonality is not a significant component of rock.

There may be such a thing as a blues scale (with or without a lowered fifth scale degree), as in Gershwin examples, but this has nothing to do with rock music, which borrows only from a blues that colors a structural major mode with minor-pentatonic melodic borrowings.

The blues scale may not be a typical feature of rock vocal melodies, but it is the bedrock of rock guitar solos. Indeed, a great many lead guitarists do not know any other scales. A central stylistic difference between a jazz soloist and a rock soloist is that the jazz soloist will generally follow the chord progression, whereas the rock soloist will stick to a single pentatonic or blues scale regardless of the underlying harmony. A typical case in point is “Ophelia” by The Band (1975). It has a richly functional ragtime-style chord progression full of secondary dominants. However, lead guitarist Robbie Robertson does not follow the changes at all; he simply plays the blues scale over the entire form.

The natural synergy between the blues and the guitar is partially due to an accident of ergonomics: the pentatonic and blues scales are easier to visualize and play than the diatonic scales. Informally trained guitarists (including the author) typically learn the pentatonics first, and then add pitches to them to form additional scales. This approach is not unique to guitarists. Greenblatt (2005) presents a similar method aimed at improvising horn players. His text begins with major and minor blues, and then adds additional pitches to round out fuller diatonic and modal harmonies.

Conclusion

Abandonment of formal music study is epidemic among Americans. Of those high school students in North America who have elective music programs available to them, only five percent choose to enroll (Lowe, 2012). These low enrollment figures are startling when one considers the central role of music in the inner lives of adolescents. There are a variety of reasons why young people are alienated from studying music in school, but surely one of them must be that the music theory being taught does not align with or acknowledge the music that they find most meaningful. The rules of tonal theory describe (or prescribe) a foreign musical culture.

The content, historical development and pedagogy comprising present-day music education and music teacher preparation in the United States of America (USA) continues to reflect a predominantly Western European cultural perspective (Kindall-Smith 2011, 375).

Under the rules of tonal theory, blues-based music is either ‘wrong’ or simply inexplicable. In order for common-practice tonal theory to describe present common practice, it should expand to include blues.

The case for amending music theory to encompass the blues is not just musicological; there is a crucial social justice component as well. Just as the descendants of the African diaspora have been oppressed and disenfranchised politically, so too has their musical culture been historically delegitimized. It is time to amend the situation.

References

Baker, D. (1988). Jazz Improvisation: A Comprehensive Method for All Musicians. Los Angeles: Alfred Publishing.

Browne, P. (2001). The Guide to United States Popular Culture. Madison, WI:: Popular Press.

De Clercq, T., & Temperley, D. (2011). A corpus analysis of rock harmony. Popular Music, 30(01), 47–70.

Everett, W. (2004). Making Sense of Rock’s Tonal Systems. Music Theory Online, 10(4). Retrieved from http://www.mtosmt.org/issues/mto.04.10.4/mto.04.10.4.w_everett.html

Feld, S. (1988). Notes on World Beat. Public Culture Bulletin, 1(1), 31–37.

Green, L. (2002). How Popular Musicians Learn: A Way Ahead for Music Education. Ashgate Publishing Group.

Greenblatt, D. (2005). The Blues Scales. Petaluma, CA: Sher Music Co.

Harrison, M. (2001). Contemporary Music Theory Level Three: a Complete Harmony and Theory Method for the Pop and Jazz Musician (pp. xii, 298). Harrison Music Education Systems: Hal Leonard Corp.

Hughes, B. (2011). Harmonic Expectation in Twelve-Bar Blues Progressions. Florida State University. Retrieved from http://diginole.lib.fsu.edu/cgi/viewcontent.cgi?article=2404&context=etd

Jaffe, A. (2011). Something Borrowed Something Blue: Principles of Jazz Composition (p. 285). advance music GmbH.

Jones, L. (1999). Blues People: Negro Music in White America. New York, New York, USA: Harper Perennial.

Kubik, G. (2005). The African matrix in jazz harmonic practices. Black Music Research Journal, 25(1), 167–222.

Levine, M. (1995). The Jazz Theory Book. Sher Music Co.

McClary, S. (2001). Conventional Wisdom: The Content of Musical Form. Oakland, CA:University of California Press.

Roberts, T. (2011). Michael Jackson’s Kingdom: Music, Race, and the Sound of the Mainstream. Journal of Popular Music Studies, 23(1), 19–39.

Schwartz, R. (2007). How Britain Got the Blues: the Transmission and Reception of American Blues Style in the United Kingdom. Aldershot: Ashgate.

Stoia, N. (2010). Mode, Harmony, and Dissonance Treatment in American Folk and Popular Music, c. 1920–1945. Music Theory Online, 16(3). Retrieved from http://www.mtosmt.org/issues/mto.10.16.3/mto.10.16.3.stoia.html

Stoia, N. (2013). The Common Stock of Schemes in Early Blues and Country Music. Music Theory Spectrum, 35(2), 194–234.

Tagg, P. (2009). Everyday Tonality. New York & Huddersfield: The Mass Media Scholars Press. Retrieved from http://tagg.org/html/FFabBk.htm

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Van der Bliek, R. (2007). The Hendrix Chord: Blues, Flexible Pitch Relationships, and Self-standing Harmony. Popular Music, 26(2), 343–364.

Wagner, N. (2003). “Domestication” of Blue Notes in the Beatles’ Songs. Music Theory Spectrum, 25(2), 353–365.

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Digital audio basics

Before you can understand how digital audio works, you need to know a few things about the physics of sound. This animation shows a sound wave emanating through the air from a circular source — imagine that it’s a drum or cymbal.

Spherical pressure waves

As you can see, sound is a wave, like a ripple in a pond. Imagine that your ear is at the bottom center of this image. The air pressure against your inner ear is rhythmically increasing and decreasing. Your brain senses how wide those swings in air pressure are and how often they’re happening, and you experience the result as a sound.

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My music education

I’m writing a chapter of the forthcoming Oxford Handbook of Technology and Music Education. Here’s a section of what I wrote, about my own music learning experiences.

Most of my music education has happened outside of the classroom. It has come about intentionally, through lessons and disciplined practice, and it has come about unintentionally, through osmosis or accidental discovery. There has been no separation between my creative practice, my learning, and my teaching.

My formal music education has been a mixed bag. In elementary school, I did garden-variety general music, with recorders and diatonic xylophones. I don’t remember enjoying or not enjoying it in particular. I engaged more deeply with the music my family listened to at home: classical and jazz on public radio; the Beatles, Paul Simon and Motown otherwise. Like every member of my age cohort, I listened to a lot of Michael Jackson, and because I grew up in New York City, I absorbed some hip-hop as well.

In middle school we started on traditional classical music. I chose the cello, for no good reason except that I had braces and so was steered away from wind instruments. I liked the instrument, and still do, but the cello parts in basic-level Baroque music are mostly sawing away at quarter notes, and I lost interest quickly. Singing showtunes in chorus didn’t hold much appeal for me either, and I abandoned formal music as soon as I was able.

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Sucker MCs

Sasha Frere-Jones was recently asked by The Guardian to make a list of perfect songs. I don’t agree with all of his choices — Taylor Swift? — but I can definitely get behind his nomination of “Sucker MCs” by Run-DMC.

This track was the B-side to Run-DMC’s first single in 1983, and was produced by Larry Smith of and Davy DMX of Orange Krush (thus the subtitle “Krush Groove 1.”) It’s beautiful in its simplicity: two guys rapping, an Oberheim DMX drum machine, some turntable scratching, and nothing else. It’s the most minimalist hip-hop song I know of, other than “Top Billin’” by Audio Two.

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