Legal Question in Entertainment Law in California

Re: can one prod co keep you from working for another?

Generally, as long as the performer isn't currently bound under an exclusivity clause, the prior employer can't prevent the performer from working for another company.

If the contract DOES contain an exclusivity clause, and the contract is still in effect, (i.e., the term of exclusivity has not expired), then it is binding, and the performer CAN be prevented from working for others (in California, there's a minimum threshold amount of compensation the performer must be paid before the courts will enforce this provision with an injunction, but even if this amount has not been guaranteed the performer may still be held liable for damages to the first production company.)

Without seeing the contracts in question, it's impossible to advise you further.

Re: can one prod co keep you from working for another?

Also - this isn't about "Right to work".

"Right to work" is a reference to labor law principles which (in some states) prevent enforcement of certain union-only employment provisions.

From wikipedia: Right-to-work laws are statutes enforced in twenty two U.S. States, allowed under provisions of the Taft-Hartley Act, which prohibit trade unions from making membership or payment of dues or "fees" a condition of employment, either before or after hire.

California is not a Right To Work state in any case