The Phantom of the Opera is a musical with music by Andrew Lloyd Webber, lyrics by Charles Hart, additional lyrics by Richard Stilgoe and a libretto by Lloyd Webber and Stilgoe. Based on the 1910 French novel of the same name by Gaston Leroux, it tells the tragic story of a beautiful soprano, Christine Daaé, who becomes the obsession of a mysterious, masked musical genius living in the subterranean labyrinth beneath the Paris Opéra House.

Musical theatre is a form of theatrical performance that combines songs, spoken dialogue, acting and dance. The story and emotional content of a musical – humor, pathos, love, anger – are communicated through words, music, movement and technical aspects of the entertainment as an integrated whole. Although musical theatre overlaps with other theatrical forms like opera and dance, it may be distinguished by the equal importance given to the music as compared with the dialogue, movement and other elements. Since the early 20th century, musical theatre stage works have generally been called, simply, musicals.