That one weird chord in “Sir Duke”

We’re coming up on the 50th anniversary of Songs in the Key of Life’s release, and I plan to put in some quality musicology on it. I’m starting now, with a look at a single chord in “Sir Duke”, the one that first appears at 0:48 in the chorus:

The song is in B major. The chorus goes like this: “(B) You can feel it all (???) over, (Emaj7) you can feel it all (C#m7) over (F#7sus4) people.” All of this except for the mystery chord is plain vanilla Western tonal music. The first chord is the tonic B. The last two chords are ii and V in B major, setting us up for a cadence into the B chord on the next phrase. The Emaj7 is subdominant, like C#m7, and you could think of those chords as more or less interchangeable.

Fine. So what about the mystery chord?

Well, the melody notes on the word “over” are A-sharp and G-sharp, the seventh and sixth degrees of the B major scale. So what chord could logically go under there? First, let’s consider chords from within the key.

• Bmaj7 – continuing the B chord from the first measure is boring but it makes sense.
• C#m7 – unsatisfying because it makes the harmonic rhythm awkward, but it does fit the notes.
• D#m7 – works great, makes a nice Puff schema leading into the IV chord.
• Emaj7 – moving to the IV chord a measure early creates lopsided harmonic rhythm, but it’s not unmusical.
• F#7 – also fits the notes, but also makes for goofy harmonic rhythm.
• G#m7 – the vi chord works perfectly, it sets us up for a variant on the classic doo-wop progression, I-vi-IV-V.
• A#ø7 – vii chords are not idiomatic to R&B, so while this has a nice murky quality, it’s too stylistically incongruous.

So, those are the choices from within the key. How about from outside the key?

• D7#11 – the substitute dominant in the key of C# minor, so it resolves very nicely to the C#m7 chord, and visiting Emaj7 along the way adds to the jazz flavor.
• D#7 – deceptive cadence into the Emaj7 chord, beautiful voice leading.
• G#7 – my favorite choice, because G#7 is the V7 chord in C# minor and makes perfect sense resolving to C#m7 even if you do go to Emaj7 first.
• A#7 – doesn’t make any functional sense really but sounds kind of cool from a voice leading perspective.

Okay, so those are eleven possible chords, some of which sound better than others, and none of which sound as good as Stevie’s chord, but all of which have some kind of logic to them. Here’s a track where I use all of those chords under Stevie’s isolated vocal.

But in the actual song, Stevie uses none of the chords I proposed. He uses Fm7.

Fm7? In the key of B major? Why? What possible musical logic does it have? The answer is that it sounds great, so, who cares what the logic is. But seriously, I have tried every explanation I could think of for why that chord should sound good. The voice leading into Emaj7 is pretty smooth, but that’s all I’ve got. Maybe Stevie was thinking of the #IV°7 chord, so, F°7? But that chord sounds terrible under the melody and doesn’t flow very well into the other chords either. Did Stevie adjust the F°7 so it had C instead of B and E-flat instead of D?

Someone on Reddit has another possible explanation, which I will adapt a bit: We’re in the key of B major. The relative minor key of B major is G# minor. The parallel major key to G# minor is G# major, enharmonically Ab major. And the relative minor key of Ab major is F minor. So, uh, there you go, Fm7 is the relative minor of the parallel major of the relative minor of B major. Maybe it’s what Stevie was thinking! Probably not. Probably he was just putting his fingers on the keys, looking for interesting sounds, and found this. Maybe he played it by accident and liked it. Or maybe he’s just a much more advanced harmonic thinker than the rest of us–I would believe that easily.

Adam Neely thinks Stevie might have been evoking Duke Ellington with this chord–that’s a highly plausible theory.

I don’t know of a single other piece of music by anyone, ever, that uses the minor seventh on the sharp fourth of a major key. Not one! People use major chords a tritone apart pretty often. That’s just the V/V chord. They use a major chord on the sharp fourth in a minor key occasionally for the same reason. Every once in a while, you hear minor chords a tritone apart in late Romantic music and John Williams film scores. But a minor chord on the sharp fourth in a major key? I can find precisely zero other examples in music history.

So why does this matter? As weird as the Fm7 chord is from a logical perspective, it doesn’t sound weird in context. “Sir Duke” is not a weird song! It’s mildly eccentric in places, but there’s nothing remotely difficult or off-putting about it as a listening experience. Small children understand it immediately. Musically uneducated adults do too. This is what makes Stevie Wonder so magical, that he can make such an unconventional musical choice sound perfectly natural.