Cal. LAB § 2855

(a) Except as otherwise provided in subdivision (b), a contract to render personal service, other than a contract of apprenticeship as provided in Chapter 4 (commencing with Section 3070), may not be enforced against the employee beyond seven years from the commencement of service under it. Any contract, otherwise valid, to perform or render service of a special, unique, unusual, extraordinary, or intellectual character, which gives it peculiar value and the loss of which cannot be reasonably or adequately compensated in damages in an action at law, may nevertheless be enforced against the person contracting to render the service, for a term not to exceed seven years from the commencement of service under it. If the employee voluntarily continues to serve under it beyond that time, the contract may be referred to as affording a presumptive measure of the compensation.

(b) Notwithstanding subdivision (a):

(1) Any employee who is a party to a contract to render personal service in the production of phonorecords in which sounds are first fixed, as defined in Section 101 of Title 17 of the United States Code, may not invoke the provisions of subdivision (a) without first giving written notice to the employer in accordance with Section 1020 of the Code of Civil Procedure, specifying that the employee from and after a future date certain specified in the notice will no longer render service under the contract by reason of subdivision (a).

(2) Any party to a contract described in paragraph (1) shall have the right to recover damages for a breach of the contract occurring during its term in an action commenced during or after its term, but within the applicable period prescribed by law.

(3) If a party to a contract described in paragraph (1) is, or could contractually be, required to render personal service in the production of a specified quantity of the phonorecords and fails to render all of the required service prior to the date specified in the notice provided in paragraph (1), the party damaged by the failure shall have the right to recover damages for each phonorecord as to which that party has failed to render service in an action that, notwithstanding paragraph (2), shall be commenced within 45 days after the date specified in the notice.