Musical theatre is a form of theatre that combines songs, spoken dialogue, acting, and dance. The story and emotional content of the piece – humor, pathos, love, anger – are communicated through the 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 of the works. Since the early 20th century, musical theatre stage works have generally been called, simply, musicals.
There is no fixed length for a musical. While it can range from a short one-act entertainment to several acts and several hours in length (or even a multi-evening presentation), most musicals range from one and a half to three hours.