Ok here's the deal. Last fall my combo (trumpet/piano/bass - we need a drummer) picked up a guitarist. We knew him a little and he could play so we thought why not. And for a while things went well. But lately things aren't going as well. This guy is very enthuiastic and loves (or should I say has no life other than) music. So he starts this thing where he's playing other people's instruments. Mostly piano, but my bass too. He picks things up quickly and had already played piano so it gets to the point where he is constantly playing piano-more than guitar, and hes pretty good. Now our piano player is understandbly very annoyed by this. And it gets worse. Last week at a gig the piano player's bro is playing one tune w/us on guitar and the guitarist literally pulls my bass out of my hands. (He wasn't playing because the piano player's bro was using his guitar) Then when I take it back he moves on to try to get on the piano. Basically he's been doin a lot of **** like this and now he wants to take piano lessons from the piano player's teacher, who is worried he'll lose his spot in a school jazz band next year because of all this. Now all this would be a problem by itself but there's more. When we play together he's very critical. He always gets way into in own thing and plays these weird out of place patterns and chords, obviously not listening, then he tells us we need to listen and adjust to him. You're not the bandleader buddy! Sorry for the long post, but my question is simple. How do I deal with him? I dont nesscarrily want to kick him out, but I have to do something!!!