Here’s a short excerpt from my blues tonality paper that I thought would stand alone well on its own.
How do we decide that a song is rock, or folk, or country, or country-rock, or folk-rock? Nearly all American popular and vernacular is informed by blues. We can use this fact to help delineate overlapping and vaguely defined genre boundaries. Just as we can explain genre in terms of characteristic rhythms and timbres, so too can we explain it in terms of the amount of blues harmony present. Good pop and jazz practitioners already do this implicitly. A guitarist or singer needs a sense of how much blues tonality to use in order to sound more characteristically ‘jazzy’ or ‘country’ or ‘rock.’
Let’s use the example of funk. Aficionados like me know when music is funky. But how do we know? The most obvious characteristic to point to is the beat. But you can also hear funk rhythms in disco, hip-hop, R&B, rock, and even country — Dolly Parton’s “Jolene” is super funky. We can distinguish funk as a genre more specifically using its harmonic content. Funk is the most heavily blues-based genre aside from blues itself. While rock and country combine blues harmony with diatonicism, funk adds in jazz harmony instead.
Let’s look at a specific pair of examples: “Jungle Boogie” by Kool & The Gang and “Inside and Out” by the Bee Gees. Why is the former funk and the latter disco? It’s not the rhythms. Both songs have impeccably funky beats. The difference is in the harmony. “Jungle Boogie” has no chord changes and all of its melodic components are blues, with some jazzy chromatic embellishment.
“Inside and Out” has a blues-inflected verse, but the rest of the song is modal or diatonic. That’s why it’s disco and not funk.
Country music has its share of blues harmony, but it’s mostly diatonic, and rarely if ever introduces jazz harmony. It’s helpful to look at the example of “Lovesick Blues” by Hank Williams (1949). In spite of the name, the song is not blues at all; it’s as straight a country song as you could ask for. The harmony consists entirely of diatonic tonality that wouldn’t sound out of place in Mozart. The word “blues” in the title refers more to the song’s melancholy tone, though you can also detect blues inflection in Hank’s flattened thirds.
George Gershwin and James P. Johnson notwithstanding, European-descended classical music can be characterized by its near-total absence of blues tonality.
The most stylistically eclectic musicians will occupy correspondingly larger parts of the diagram. For example, The Beatles’ music touches every section. While most of their music is a blend of diatonicism and blues, they also venture into jazz major in “Sun King” (1969), jazz minor in “Come Together” (1969), Indian-influenced drones in “Within You Without You” (1967), and atonality at the end of “Strawberry Fields Forever” (1967).
What do you think? Are there any good examples of blues harmony being useful for identifying and distinguishing genres? Maybe in different versions of the same song by different people? Let me know in the comments.