Guest appearance

In show business, a guest appearance is the participation of an outsider performer (such as a musician or actor) in an event such as a music record or concert, show, etc., when the performer does not belong to the regular cast, band or other performing group. In music, such an outside performer is often referred to as a guest artist. In performance art, the terms guest role or guest star are also common, the latter term specifically indicating the guest appearance of a celebrity. The latter is often also credited as "special guest star" or "special musical guest star" by some production companies.