Herbie Hancock's trill, that plays from the beginning of the track, causes a lot of confusion among people who try to transcribe it. It was not, as far as I know, written into the original sketch in the way that Hancock plays it - I believe that I have successfully found the real notes that he plays.

They aren't G || AB (where || represents tremolo), nor are they G || A, but in fact EA || GF. Try it - it sounds a lot more correct than anything I've seen written. I also believe this doesn't actually change for the C Chord. For the D7#9, it stops all together.

Also, I think it's worth noting here that the "four bar interlude" that mawa mentions isn't actually an interlude at all. Also, the chord changes he notes are incorrect. The form of the piece is, in fact, a 12 bar blues, plain and simple. The chords are as follows:

| G7 | G7 | G7 | G7 |
| C7 | C7 | G7 | G7 |
| D7#9 | Eb7#9 D7#9 | G7 | G7 |

Note: the last two bars in this form are often played as follows:

| G7sus4(omit 3) Gmaj9 | G7sus4(omit 3) G7 |