One of the high points of my musical career was playing in a cover band in college called Harsh Mouse, and one of the high points of our repertoire was this song.
This irresistible groove was sampled from “Bring In The Birds” by Herbie Hancock, from the score of Michael Antonioni’s film Blow-Up.
Herbie’s tune is fun in that Austin Powers way, but the two-bar intro is its best feature. Deee-Lite had the good sense to recognize that intro as the reliable dance-floor-filler that it is. Back in the 90s, there was no Wikipedia, so I only just learned that the track includes Q-Tip and Bootsy Collins.
The “Groove Is In The Heart” riff is more or less a steady stream of eighth notes over a two-chord progression–more on those two chords in a bit. Its main rhythmic excitement comes from the anticipated downbeat in the second bar. The first beat in a measure is the strongest one, the one where you most expect a major musical event like a chord change to happen. “Groove Is In The Heart” fakes you out by hitting the root of the new chord change a half beat early. The resulting metrical instability gives the groove its deliciously off-kilter feeling.
The chord progression of “Groove Is In The Heart” is a funk standby: A♭7 and D♭7, two dominant seventh chords a fourth apart, alternating back and forth for the entire duration of the tune. Simple though it is, this progression is hard to explain using the rules of Western tonal harmony. Dominant seventh chords are “supposed” to resolve down a fifth, so the A♭7 should resolve to D♭. Indeed it does, so it would appear that D-flat is our home key. But the D♭ chord is a dominant seventh too, and tonal theory says that it’s supposed to resolve to G-flat. It certainly wouldn’t lead us back to A♭7. Besides, dominant seventh chord or not, A♭7 feels like the “home base” chord because of its metrical position.
So Western tonal theory doesn’t shed much light on “Groove Is In The Heart.” But this is a funk groove, and those are usually modal. So maybe the two chords are implying a mode. We could think in jazz terms and treat A♭7 as emerging from A-flat Mixolydian. The scale is shown below, on the chromatic circle is on the left, and on the circle of fifths on the right. The blue lines show the A♭7 chord.
The D♭7 chord would similarly suggest D-flat Mixolydian.
Notice that the two scales are almost identical. You could rotate either of them one notch on the circle of fifths to get the other. Closeness on the circle of fifths is a good proxy for harmonic relatedness generally.
When you combine the pitches from the two scales together, you get A-flat Mixolydian with an added flat third (C-flat, which is the same pitch as B). This scale is known in jazz pedagogy as the A-flat Bebop Dorian scale.
So, there’s our mode. Problem solved, right? Not quite. When you look at the vocal melody in the chorus, there’s a prominent D natural in the fifth measure. (The transcription can’t capture all the subtle pitch inflections, but it’s as close as music notation gets.)
D natural isn’t in any of the scales we’ve talked about. This melody is a classic example of the blues scale.
Remember how I said that closeness on the circle of fifths is a good proxy for harmonic relatedness? By that standard, D natural is the weirdest note imaginable in the key of A-flat. It’s on the exact opposite side of the circle from the root. The blues scale is totally inexplicable in Western tonal theory terms. It has the flat third characteristic of minor tonality, yet it’s frequently used over major and dominant chords, as it is in “Groove Is In The Heart.” This tune is not really in A-flat major, or A-flat minor. It’s in A-flat blues tonality. That’s not a standard term in music theory, but it should be. If a harmonic practice is this common and this well-loved, we need to adapt our music theory to be able to accommodate it.