We have a rule and a process. Rule: If we are discussing the music/problem solving, no playing through amps or drumming. Process: When a song stops or ends, everyone listens to what happens. If anyone needs some time to work on a part, time is given to that and everyone else listens to what happens. Time is not to be wasted. No one is in charge all the time, but each song is "owned" by the either the person who sings it, arranged it, or wrote it. Work proceeds by consensus, and we take breaks so we "wankers" can relieve the urge to wank as well as seek other forms of comfort. At the end of rehearsal, we often plan what we will work on at the next rehearsal. An occasional wank is heard, but it is manageable.