That really struck a chord with me (pun intended). Given a set of chord changes (e.g. “All the Things You Are”), when trying to improvise I feel as though I’m driving with a square tire. If I “think” about it (i.e. not quickly enough to play it in real time) I can figure out what notes fit. I can hear the difference between, e.g., a major chord, a minor chord and a dominat seventh, but when I have to play over them it seems I forget everything I know. I don’t know if I’m “hard-wired” to hear harmony well or not. At least as liely is the possibility that I’m too easily distracted/frustrated to really figure out harmony with my ears. I seem to remember a book, “Harmony Primer” or some such — is there anyone who spells it out more clearly than others? Any recommendations along these lines?