Do I need to form an LLC or similar to sell my music?

That really depends on a few different things. How much money do you think this will bring in? What do you think is your personal liablity with this business? An LLC can separate your personal and business ets and reduce your liability. It is a great et protection tool. If you income is high enough, it can also give you significant tax benefits as well. You should seek proper counsel. If done incorrectly, it can cost you in the long run. I consult with clients daily on proper business structure. Let me know if you need istance.