Learning obliquely

I suppose all jazz musicians are familiar with the Dizzy Gillespie quote where he says, "It's taken me all my life to learn what notes not to play", or words to that effect. I was thinking about that last night at my piano lesson, as we were working on oblique movement. Don't Get Around Much Anymore is what I would consider an easy song. Standard chord progressions, nothing too hard in the melody, long bars in which to solo, in short, the kind of song I like to play. (Ellington really works that way for me.) I had been working on the oblique chord progressions, but I couldn't make the one that goes down (C7-B-Bb-A7) sound good at all. I decided to play the song for my instructor anyway and let him show me what was wrong. All at once, actually looking at the music while playing, I realized: I was trying to play the wrong notes.

For some reason, even though the melody ends on an E before going to the oblique movement chord progressions, I had it in my mind that it ended on a C. So, my mind wanted me to keep the C in the chords, which isn't entirely necessary. I also thought that because the ascending oblique movement starts on C major 7th, the descending also started on C major 7th, but it actually starts on C7. That makes a big difference when the dissonant B of the major 7th is removed. And, because we're playing jazz here, we can actually put the C# on top of the C7th chord, and use it as the oblique anchor, since it is part of the A7th finishing chord. Amazingly, after two minutes of paying attention to the written notes and my instructor pointing out the obvious, I could play the song.

So, what's that got to do with Dizzy? Well, I gained some insight into what notes not to play: Don't play the wrong ones!