Dtyjlui

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.

The C7♯11 is really just a re-spelled augmented-sixth chord that moves right into V7. If we think of C B♭ as C A♯, we see how easily these two pitches push towards the root of the B7.

And depending on how it's voiced, the B♭7♯11 is really an altered dominant of the succeeding A7. E7, the standard dominant of A, is E G♯ B D. The B♭7♯11 is really a tritone substitution of this E7, since the B♭7♯11 has E (that's the ♯11), G♯ (but spelled as A♭, which is the 7), and D.

As such, this progression is really just:

• V7


• Extended augmented sixth


• V7


• Altered V7 of IV


• IV7


• V7♯9


• I

Very basically, it's a huge perfect cadence. A page of the tonic (Ebm), a move to the dominant (Bb7), then back home to the tonic.

In more detail, the Bb7 section is decorated by sliding up and down - a musical term could be 'planing' - up a semitone to Cb7, back to Bb7, down a semitone to A7, down again to Ab7, back to Bb7.

(The actual chords are a bit more funky than those basic descriptions. But same idea.)

Apart from the overall Tonic - Dominant - Tonic plan, we're not looking for functional harmony here. Yes, Cb7 COULD be a 'b5 substitution for the dominant-of-the-dominant', but it really isn't. It's just the next chord up. The sort of thing your fingers slip easily into on a keyboard or fretboard. Don't over-think it! Not every chord progression has to be functional.

Others have already given several explanations from different viewpoints, but let's try one more. The chords are just the dominant chord i.e. V chord and the VI a semitone above it, and then there's a IV before a final V dominant and going to home base I. Let's forget the "Bb7#11" for now and try to make a very simple "for dummies" reduction of it, stripping away some of the blues and jazz complications.

Is that easier to understand? In my opinion, you could jazz that up to get the original.

V - VI - V is a very common change chord variation of the dominant in minor (in major the bVI would be a an enharmonic reinterpretation of the augmented IV56 - so called “mozart fifths”

V - bV - IV (resp. (V - #IV - IV) is a popular passage of measure 9 to 10 in the 12 bar blues pattern

finally:

IV - V the last sequence is part of the well known cadence