Hello everyone. I am beginning to analyze the harmony to "Speak Like A Child" By Herbie Hancock.

The Chord Sequence for the 1st Part Of the Song is :

|Db7(#9)|Db7(#9)| Ab7(#9)| E7sus4 A-7|

|Gbmaj7(#11)|Gbmaj7(#11)|Gb dim7| Gbdim7| Eb7sus4|

|Eb7|Eb-7| D7#9| G-7 C7| Fmaj7 Bb-7|


To Me it has a key center of Aminor but with a lot of Substitutions and modulations.

The Curious thing I have found is if we treat the Db7(#9) as an inversion of a type of E dominant chord we get the following intervals:

Db7(#9) = Db,F,(Ab),Cb or B, And E

which gives us = 13th,b9,3rd,5th and Root of and E13b9.
Choosing A voicing with the E on the top or bottom really helped bring this out for me.

Moving to the Ab7(#9) I can see it a 5th above the original chord so may suggest it can substituted as a B13b9 this would lead nicely as a II chord into the following V and I formed by the E7sus4 and A-7.

Next I would take Bb7 as a straight tritone substitution of E7 the V.
Bb-7 And Eb7 and a II and V of Db major....