Speed Sketching Musicians

Speed sketching is about catching the movement impact or emotion of a subject in as quick a time as possible and often with as few gestures as possible.  Whenever I hear musicians performing it always makes me feel like playing along with them.  Lately I've started trying to draw them while playing.  Normal people are hard enough to draw but musicians are often in constant motion.  

Here are a couple of sketches I felt got close to expressing some of the experience of seeing them live.