Defining key centers with rhythm

Let’s say you have two chords, G7 and C. According to Western classical theory, these two chords establish that you are in the key of C. The G7 is tense and unresolved, and it makes you yearn for the calm stability of C. Music theory resources are full of language about how dominant seventh chords are always dissonant and always need to be resolved. For example…

• Wikipedia: “Dominant seventh chords contain a strong dissonance, a tritone between the chord’s third and seventh.”
• Andre Mount: “Whereas a triad may be consonant, a seventh chord is inherently dissonant.”
• Jason Solomon: “The chord progression I-V-I is the essence of tonal harmony. The framing tonic chords serve as stable points of departure and return. The dominant destabilizes the tonic to set up its eventual return.”
• Alfred Blatter: “Seventh chords by virtue of their more dissonant (unstable) nature create a strong harmonic drive toward a resolution. The strongest and most familiar of these is the dominant seventh chord, which almost compels the arrival of the implied tonic chord.”

Even jazz resources use this language.

• The Jazz Piano Site: “The Dominant chord is an inherently dissonant chord because it has a tritone interval between its 3rd and 7th, and as such it wants to resolve towards the consonant Tonic chord.”
• Dariusz Terefenko: “The dominant is an antithesis of the tonic in every conceivable way: it is highly unstable, represents chords on the move, accumulates harmonic tension, and does not rest until it reaches a local or structural tonic.”

Yeah, but the thing is, this is not true! Dominant seventh chords are dissonant only in particular stylistic contexts, namely, Western European folk and classical and the musics that descend from them. In blues, rock, jazz, and lots of pop music, dominant seventh chords can be tonic chords too, and they can sound perfectly resolved. The G7 and C chords might actually be defining the key of G, not C.

This is not just music theory arcana! If you want to play the blues on a C harmonica, you need to take an instrument that was designed to play G7 and C in the key of C major, and play it backwards so that you think of it as being G7 and C in the key of G blues.

But how could this be? How is it possible that in a loop of G7 and C, G7 can act like the tonic chord just as easily as C? What is the distinguishing factor? Maybe it’s just a matter of stylistic context? If you hear a G7 chord in Mozart or Beethoven, you have a lifetime of enculturation to tell you that it’s supposed to feel unstable and in need of resolution to C. However, if you hear a tonic G7 chord in Parliament or James Brown, you will have learned to hear it as stable. But this doesn’t really explain how Parliament or James Brown make the G7 sound stable. The answer can’t be found in the chords themselves. Instead, we need to consider the underappreciated role that the metrical placement, emphasis, and repetition of chords can play in how they function.

As an experiment, I created a piece of music that only uses the chords G7 and C. In the first section, these chords act as V7 and I in the key of C, the way classical theory teaches you they should. In the second section, the chords sound like I7 and IV in the key of G. Then the two sections repeat.

Here’s the tune in Noteflight format so you can see what’s going on:

To help clarify what you’re hearing, I inserted four bars of groove between each section ,as a kind of aural palate cleanser. I also have the bassline reinforce which chords I “want” you to hear as tonic. But the effect works just fine without the break or the bassline. Without those reinforcing factors, it takes a few bars of the second section for your mind to reorient around G7 as the tonic, but it still happens reliably.

I didn’t write my tune in any systematic way, I did it intuitively. But in retrospect, here’s what I did to make myself hear C or G7 as tonic. In the first section, the C chords fall on the “and” of two. That’s a weak subdivision, but it’s such a common syncopation in American music that it practically feels like a strong beat. In the second section, the first C chord falls on the “and” of three, which is a much weaker-sounding subdivision. In the second bar, the C falls on beat four, which is so late in the bar that it makes the chord feel unimportant. In the third bar, the C gets interrupted early by the G7’s anticipated entrance. And, of course, the section ends on G7 rather than C. That doesn’t in and of itself establish G7 as tonic; it could be a half cadence that’s meant to resolve in the following bar. But after everything else you’ve heard, together with the groove-oriented context, your ear is well convinced that you are in G blues territory, so the Western classical rules don’t apply.

When I say that the V7-I cadence is harmonic whiteness, I am not just trying to be provocative. I want music theory resources to be more accurate. I want them to stop using universalizing language like the quotes at the top of this post. It’s fine to say that, in Western European tradition, the dominant seventh chord is a dissonance that wants to resolve to a triad. But it is simply untrue to say that this an inherent fact of the music, even within a solely “Western” context. The Grateful Dead demonstrate that you can turn a V7 chord into a tonic I7 just by repeating it for long enough. In my experimentation with Paulstretch, I have found that literally any chord in any piece of music will feel like a tonic unto itself if the tempo is sufficiently slow. Blues, jazz, rock and funk are all Western musics, and these musics use musical time to establish their tonics more often than they use voice leading. I want to see music theory texts acknowledge that fact.