Can someone explain the theory behind the changes in Superstition by Stevie Wonder?

Question

I'm learning Stevie Wonder's Superstition on guitar (an awesome song) and I'm really curious about the theory behind the changes in the chorus. The intro and verse are just a riff in E minor pentatonic. From the chord charts I've seen that's sometimes shown as over E7#9 and other times over Em7. Then the chorus is ... 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 B7 C7#11 B7 Bb7#11 A7 B7#9... before returning to the next verse riff on E7#9.Can someone help me to understand that chord sequence in the chorus from a music theory point of view?Thanks.

Answer 1

Superstition's chorus is a variation on the Doo-Wop changes. I-vi-IV-V. He is doing this: I-vi-bVI-V So they would be B^, G#-, G^ ,F#7(C7#11). He is simply subbing the 4 with a flat six. He is using a chromatic passing chord to replace the sub-dominant function of the 4 chord.

Answer 2

The place to start is finding the key. The original song is in Eb minor, and it looks like your version is in E minor (half step up). Let's say we're in E minor.

Analyzing consecutive dominants can be tricky, but I would analyze them as:

B7 = V7

C7#11 = subV7 of V

B7 = V7

Bb7#11 = subV7 of IV

A7 = IV7

B7#9 = V7

"subV7" means tritone substitution. You can substitute any 7 chord with a 7 chord a tritone away because these chords share the 3 and the b7. In this example, V7 of V would be F#7, which has A# (Bb) for it's 3 and E for its b7. The subV7 of V (C7) has E for its 3 and Bb (A#) for it's b7. These chords are therefore interchangeable.

The A7 to B7 makes me think of a blues pattern, which is why I analyzed as IV7 going to V7. A7 could sometimes be the V7 of VII, but since it does not go to the VII, I wouldn't analyze it like that here.

Hoping this gives you some insight, and if you need clarification on anything or further information I'd be happy to help!