In baseball, a pitcher uses a variety of different pitches to get batters to miss hitting the ball. With a curveball, the ball appears to be in one place and suddenly moves, possibly to the batter’s dismay.
The element of surprise can be effective in music too. Not necessarily random change, but in taking chances both rhythmically and harmonically. Sometimes the composition presents that itself. The main section for improvising in this week’s tune, “Curveball,” is an 8-bar section where the chords change each measure. Harmonically, they are more related to modes in my mind, both from the major and melodic minor scales. Harmonies are changing quickly here, although repeating in a pattern. The trick is create a line or texture that uses the notes in common between them. In this case, John and I start out trading a set number of bars then eventually it dissolves into more of a polyphonic texture.
To me this song is a little darker in mood, mainly due to the harmonic tension perhaps, somewhat ECM-ish for these shorter, grayer days.