My wife got me the sound track of Ken Burns documentary on Jazz, and I listened a lot. Armstrong and Ellington struck me as the transcendent geniuses doing two different things. Armstrong it seems to me found the essential elements and subtracted out the parts that werent the main elements. Ellington it seemed to me did the opposite, putting into chords things I would never think of in a million years, combining notes that I would have thought absurd to combine but which somehow sounded amazingly good together. I dont know about music theory or anything like that but I see Steely Dan and Ellington as similar, combining notes that I would never dream should be together but creating a sound that was novel, unexpected, and amazingly wonderful sounding. I had a client who was a composer who came from the USSR. She told me she couldnt imagine how I could do my work, tax planning stuff. I told her I could not fathom how she could create music. But she told me that it isnt as hard as I thought, that in school they taught her how to do it, and that I could learn it too. I didnt believe her. I still dont believe her. Music is a mysterious magic only gods can put into the heads of Ellington, Armstrong etc. I just cant imagine how they do it.