All this stuff about the bike, his family, etc is not directly relevant, so don't let any of that cloud the issue. Not being able to play parts he once could, not practicing, not doing what he's suppoded to be doing with his teacher, all sounds like he doesn't want to be in the band anymore. Since he's a friend , maybe he doesn't want to quit and jeopadize your friendship, so he's doing this weird passive agressive stuff to force you to make the move or to make the band implode. Have a heart-to-heart and find out how he really feels about the band. Let him know it's OK for him to bow out and you'll still be friends. If he still want to be a part of the band, then warn him to get his s### together or he won't be.