A choir, chorale, or chorus is a musical ensemble of singers. Choral music, in turn, is the music written specifically for such an ensemble to perform. http://en.wikipedia.org/wiki/Choir

The performing arts differ from the plastic arts insofar as the former uses the artist's own body, face, presence as a medium, and the latter uses materials such as clay, metal or paint which can be molded or transformed to create some art object. - Wikipedia at: http://en.wikipedia.org/wiki/Performing_arts