Harmonic rhythm in two-chord shuttles

We devote a lot of attention in music theory pedagogy to chords. But it isn’t enough to look at what the chords are; you have to consider when they are too. The placement of chord changes in musical time is called harmonic rhythm. The easiest way to understand this idea is to look at songs (or song sections) with only two chords. Philip Tagg calls these two-chord shuttles.

You can’t get much harmonic variety out of a two-chord shuttle by definition, but you can create interest by considering the timing of those two chords.

Simple cases

“Can I Kick It” by A Tribe Called Quest has standard one-measure harmonic rhythm (as does its sample source, “Walk on the Wild Side” by Lou Reed): a bar of C, a bar of F, a bar of C, a bar of F.

“Fire on the Mountain” by the Grateful Dead is the same idea, but at half the speed: two bars of B, two bars of A, two bars of B, two bars of A.

“Family Affair” by Mary J Blige uses the same two-bar harmonic rhythm: two bars of C#m, two bars of G#m.

The groovy soulful part of “The Great Gig in the Sky” by Pink Floyd (1973) is yet another two-bar harmonic rhythm: two bars of Gm7, two bars of C7. This chord sequence is called the Dorian shuttle, and we will be seeing more of it.

Syncopated harmonic rhythm

“Oye Como Va” by Tito Puente, as famously covered by Santana (1970), is a Dorian shuttle with a one-bar harmonic rhythm, alternating Am7 and D7. However, each D7 is anticipated by half a beat. This is only a mild disruption to the harmonic rhythm by the standards of Latin music, but it’s still very hip.

More complicated cases

“Lively Up Yourself” by Bob Marley has a simple one-bar harmonic rhythm alternating C7 and F7, but it sounds much more complicated than that. This is because the different layers of the arrangement are constantly pushing and pulling, anticipating and delaying the implicit chord changes.

“Everything is Everything” by Lauryn Hill is a two-chord shuttle with a four-bar structure.

This tune is basically an antisymmetrical four-bar loop: E to Am, then Am to E. But the second chord in each pair is anticipated by half a beat. It makes more sense when you see it in notation:

Everything is Everything – Lauryn Hill

So far, every loop I’ve discussed has alternated the tonic chord with some other chord. You can almost always assume that the first chord in the loop is the tonic. Philip Tagg would say that a chord’s metrical placement in the loop is the main factor in determining its tonicity. But what if the I chord isn’t in the strong position? Two of Michael Jackson’s best-loved originals use this idea. “Don’t Stop Til You Get Enough” is a two-bar harmonic rhythm in B Mixolydian, but the first chord in the loop is A, and the second one is the tonic B.

“Wanna Be Startin’ Somethin'” uses the same idea. It’s a one-bar harmonic rhythm in E Mixolydian, with D as the first chord and E as the second.

Ray Charles’ recording of “You Are My Sunshine” is fascinating for several reasons. I use it to teach swing, but it also has extremely hip harmonic rhythm.

The verses and choruses only use two chords, F7 and Bb7, but they aren’t placed in a simple loop. Instead, Ray has the harmonic rhythm speed up over the course of the verse, and the two chords also flip the weak/strong position a few times too.

| F7  | F7  | F7  | F7  |
| Bb7 | Bb7 | F7  | F7  |
| Bb7 | Bb7 | F7  | Bb7 |
| F7  | Bb7 | Bb7 | F7  |

As in the Bob Marley song above, there’s a further complexity in the way that the different instrumental layers are harmonically misaligned. The bass and piano change chords on the downbeats, but the horn section chord changes are delayed by a beat. It’s so hip!

I wrote some common harmonic rhythms for my students to sing/play along with, and you can try them too:

I7 – IV7 harmonic rhythm

For many more examples of two-chord songs, take a look at Andrea La Rose’s excellent Substack.

There’s a larger philosophical discussion about two-chord shuttles that’s beyond the scope of Aural Skills II. It turns out that you can make any two chords sound “functional” simply by repeating them over a groove. I explore this idea in a discussion of “Love Rollercoaster” by the Ohio Players and “Genius of Love” by the Tom Tom Club. It doesn’t just work with normal chords! Mashing your fist on the piano works fine too. As long as the groove is tight, it makes sense of whatever groups of pitches you see fit to repeat on top of it. This is an idea that needs a lot more musicological attention.