In Oleo by the Miles Davis Quintet at 0:17, Horace Silver plays a C Maj7/D voicing during the D7 chord at the bridge creating a ?D11 chord (if I am transcribing it correctly !). My question is what is the purpose of playing the 11th if it creates a strong dissonance with the third (F#)?
The idea behind CM7/D, Dsus13, etc. are well discussed. However, what's actually happening in the recording is a bit different from that.
"Oleo" is based on Rhythm changes in Bb, so the expected/characteristic bridge would be
D7 / / / | D7 / / / | G7 / / / | G7 / / / | C7 / / / | C7 / / / | F7 / / / | F7 / / / |
That is, a sequence of V-I relationships.
However, the Quintet makes a common modification, substituting the
ii chord of G for the initial D7, making a complete
ii-V leading to the G chord.
A-9 / / / | D7#9b13 / / / | G7#9(13) / / / | G7#9(13) / / / |
Thus, the chord identified as CM7/D is actually an A-9. There's no D at all, either in the piano or the bass.
CMaj7/D is D G C E B, which is a D13sus chord, not D11. It's fine to play a 7sus chord in place of a dominant 7th chord in jazz, and of course fine to play 9sus and 13sus chords here, too. The substitution just has a different sound; I suppose you could say that this is its "purpose".
There might be potential problems if someone else in the band plays a major 3rd, but:
- any note can work if you make it work
- this is why improvising musicians have to listen to each other and play accordingly
The 'purpose' is to create a strong dissonance!
Music tends to go from tension to release, the release being giving a feeling of relief, if you like, after some angst. That angst, here, is produced by a dissonant chord.
As ex nihilo says, Cmaj7/D has the same notes as Dsus13. Dsus13 replaces the F♯ with G, but even if someone else plays an F♯ over it, it doesn't have to clash unmusically. As I keep telling students - Any note can and will fit over any chord, it's just knowing how and where to play it.
No 'function' beyond the basic D7 harmony. Just a colourful extension.
You can add a 9th or a 13th to a dom7 shape chord. You can go further and add a whole chord to the upper structure!
Don't try to analyse it too hard. Just recognise how it's constructed, what it sounds like, and (if you think it sounds good) put it in your musical tool-kit.
Maybe it could be described in the 'pile of thirds' system too. To take another example, here's a pretty standard 'dirty' final tonic. Would you find it easier to read as C13(#11) or D/C7? (Hint, there's no right answer.)