[practice] Single-stroke warmup

Play one bar of sixteenth notes with your right hand, followed by a bar of alternating thirty-second notes starting with your left, a bar of sixteenth notes with your left, and a bar of alternating thirty-seconds starting with your right. This gets at what Dave Weckl talks about in his first video, which is that fact that your hands seem to play faster in a single stroke roll then they do by themselves.