Musical theater is a form of theater 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.
The sung lyrics of a musical are referred to as its libretto (originally an opera term); the music itself is the score; and the combination of the spoken dialogue and the sung libretto is often referred to as the book of the musical.
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: other efforts, such as the spectacularly unsuccessful series Cop Rock have been met with less acclaim.
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). These have become known primarily as stunts rather than for their intrinsic merit.
See also Broadway, musical film.