theater is a form of theatre, the branch of the performing arts
concerned with acting out stories in front of an audience using
combinations of speech, gesture, music, dance, sound and spectacle -
indeed any one or more elements of the other performing arts. In
addition to the standard narrative dialog style, theatre takes such
forms as opera, ballet, mime, kabuki, Chinese opera, mummers' plays
Musical theater is a form of combining music, songs,
dance routines, and spoken dialogue. It is closely related to opera,
being distinguished by the use of popular music of various forms, and
the use of non-sung dialogue (though some musicals are entirely sung,
and some operas have spoken dialogue, such as Carmen), and the
avoidance of many operatic conventions.
Musical theater has been the basis for a number of successful musical
movies. Efforts to adapt musical theater to television have been more
problematic. Some successful television adaptations include
Cinderella, and Peter Pan.
Some popular televisions series have set one single episode in the
style of a musical as a play on their usual format. (Examples include
episodes of Ally McBeal, Buffy The Vampire Slayer's episode "Once More
with Feeling", or Oz's "Variety").