This was more theoretical than concrete about a specific song, just looking at some chord charts for a few songs.
I have a more "concrete" learning style so I hope you don't mind if I throw a song example out there for discussion? And if you have any specific songs you want to talk about, I love that kind of conversation.
Here's a Ray Brown performance of Duke Ellington's "Take the A Train." This is the first song that I remember ever learning as a beginner, to so prominently feature an altered chord. Ellington really hits you over the head with it; it's a signature element of the composition. In this transcription, I am referring to the D7(#5) chord, first encountered in measures 3-4. Do you find any of Ray Brown's note choices surprising over the D7(#5), or is he playing pretty much what you'd expect? (I personally really like the sound of F natural to F sharp, or you could think of it as E# to F#.)
Another interesting musical moment is the last measure of the B section. We have G7 going to G7(b9), so just in the space of 4 beats, a microcosm of the difference between altered and non-altered versions of a G7 chord. One thing I was listening for, I was curious, did Ray Brown and his trio play that b9 alteration during the solos, or only during the melody?
