Remember what your son needs is more than material comfort.
Prepare to have a heart-to-heart talk with him. Music are part of a young people's life. You can't stop him just because good communication will smooth the problems. Your son wants you to treat him as your equal while you act as a commander. That's where all the problems come from.
You'd better not put too much pressure on your son. Be a good motivator. Try to encourage him to find myself, to build up self-confidence. Cut out harsh remarks when your son falls short of your expectation.
Unconditional love is very important, because he is your son.
Homework:
Get ready to write an advice letter.