@Hayden, I really love that Bud Powell performance of TWNBAY; thanks for sharing that!
Since you mentioned that he harmonizes the entire head using the Barry Harris voicing scheme, can you explain how the Db7#11 chord at 0:23 fits into the scheme? Or maybe @Tuomo would like to take a shot at it?
The reason I ask is that the Barry Harris scheme requires that dominant chords be voiced either as b9 chords using the diminished chord voicings from the scale, or as some kind of m6 voicing over a root note (the non-diminished voicings from the major Barry Harris scale don’t contain a tritone, so they can’t be used to really voice a dominant chord). Those are the only two voicings in the Harris scheme that have tritones in them, and neither of them can be used for a #11 chord – they’re either a 7b9 voicing in the case of the diminished ones, or an aug7b9 or a plain old 9 chord in the case of the m6 structure.
I feel like @Tuomo’s “change a note” approach, while very practical for performance, really moves us a step away from the system of using voicings built from every second note of these scales that are either major or melodic minor with a b6 note added. The need to change a note means we have found a situation where the strict framework of those scales doesn’t apply. Unless I’m hearing it wrong, I think Powell’s #11 chord is a similar situation; you just can’t use the “strict Barry Harris” scheme successfully there. Of course because Powell’s voicing is a lydian dominant voicing, it comes from a melodic minor scale, so technically speaking the Abm Barry Harris scale can give you that voicing with the right selection of notes. But the notes you have to choose are not alternating notes from the scale, and in my understanding this is a departure from the Barry Harris voicing scheme.
In a similar way, the fourth bar of the bridge of “Bouncing with Bud” departs from the scheme with its D7#9 harmony.
I find it useful to know when a beautiful idea works, and when, contrariwise, you need to use a different beautiful idea.