Legal Question in Intellectual Property in California

Probably; it would be worth your time and expense to contact an intellectual property lawyer for detailed advice IF the "people" who are mis-using your performance stand to make fairly big bucks from it, or you have an urge to spend some bucks of your own to prove a point.

Intellectual-property litigation tends to be expensive, and unless you can prove that you suffered money damages, you might win the case but not get a big damages award to cover your time and legal expense. For the most part, plaintiffs' recoveries in suits like this (copyright, but probably no actual copyright registration on file) are difficult to obtain and limited pretty much to damages you can prove with hard numbers, such as actual profits from sales of the same music by the alleged infringers.

I would suggest you get an I-P lawyer to write some demand letters on your behalf before launching a lawsuit, which could be more expensive than rewarding. The exception would be if the performances in question became big commercial successes.