In the process of trying to improve both my vocabulary and my willingness to pay attention to the rest of the band when trading fours, I've just come up with a new (to me) exercise, it's tough but fun, and I think it works well so I thought I'd share the idea in case it's useful to anyone else: 1. Find a good recording of a jazz tune you know well (e.g. a blues) 2. Import the song into an audio editor 3. When the solos start, select every other 4 bars, and replace with silence. So every 4 bars, you insert silence for 4 bars. 4. The silenced parts become your time to solo, as if you were trading fours - play the song, and respond to whatever you hear every 4 bars. 5. When you're done, swap and silence the alternate 4 bars, and repeat. That's pretty much it. I'm finding it very hard to not just use chops but actually try to respond in some meaningful way, but I'm hoping this exercise will help..