Types of things a musician or songwriter might use an attorney for:
1. If you have a band, you have a business. You should have an understanding among the band members as to who owns equipment, what happens to money from gigs, what happens to money from merchandise, who owns songs, who owns the recordings of those songs, and what happens when a band member wants to leave. An attorney can help you understand these issues, make suggestions on how to handle them, and help you set up a business structure.
2. If you are a working band or musician, you are a commodity. You should think about merchandise, corporate sponsorships, tour support, and contracts with venues or promoters. An attorney can help you seek and negotiate these deals, and provide contracts to seal the deals.
3. If you are considering signing with a manager or agent, an attorney can advise you on the specifics of the deal, and help draft a solid, enforceable agreement.
4. If you are selling or want to sell your music to others, an attorney can help you seek out opportunities and advise you on any offers.
5. If you were supposed to get paid for a gig and didn't, an attorney can help you collect your money.