Is there a legal difference between using the music for commercial purposes (concert, bar...) and using it for non-profit charitable purposes? In the non-profit scenario, there are no profits for the artist to share in. All the comments here assume there is no difference but I am not sure that is the case.
Why would music be any different than any other product?
Don’t use something that doesn’t belong to you without permission or payment.
Kind of simple.
That’s a question for the MPAA. Maybe a web search will reveal the answer but if I had to guess they probably have a special event and charity license that may even be free or heavily discounted depending on how much overhead is consumed by the charity (a true charity where everything is donated, vs a charity that rents a hall and hires catering that takes 50% of the revenues). I would also guess that for most truly charitable causes, maybe even religious events, they simply don’t bother to enforce it. You could get away with it for a day without anyone finding out if it was relatively small scale. But any type of commercial use, they will want you to pay.