As used in this chapter:
(a) “Theatrical engagement” means any engagement or employment of a person as an actor, performer, or entertainer in a circus, vaudeville, theatrical, or other entertainment, exhibition, or performance.
(b) “Motion picture engagement” means any engagement or employment of a person as an actor, actress, director, scenario, or continuity writer, camera man, or in any capacity concerned with the making of motion pictures.
(c) “Emergency engagement” means an engagement which has to be performed within 24 hours from the time when the contract for such engagement is made.