I have the music for this piece, and, after listening to a recording, I realize just how little I know about jazz harmony. Herbie Hancock uses tones that, when I look at the chord on the sheet music, I can barely begin to figure out which extension he's playing. It seems as though the root is not allowed and the third is optional.
Instead, he uses a lot of flat and sharp 9s, 11s, and 13s that give the sound a really interesting sound - one that is incredibly different from my rendition, which is a lot more simple.
From an analytical aspect, this tune is interesting because Victor Young included the progression bVII7 - Imaj7 several times. As a dominant, bVII actually works well - it has lots of leading tones in jazz harmony. Here's how the basic chord resolves:
1 up half step 7
3 common tone 9
5 down half step 3
7 down half step 5
There are several leading tones, and when you play the chords, the change is very easy.
I didn't have one single emotional response to this piece. Instead, I felt very interested in the colors they were using, and relaxed by the overall mood of the performance. Even though I was primarily interested in Hancock's playing, one can never ignore Miles Davis. His cool style, intensity, and creativity really make this recording great.