Along with Jazz and Rock, the Musical has been one of the most important American contributions to the popular culture of the twentieth century and early twenty-first century. Musical shows like Oklahoma!, South Pacific, West Side Story and My Fair Lady are performed and enjoyed all over the world.

A musical is a type of theatre that aims to entertain through fusion of a dramatic script, acting, and spoken dialogue; with music, singing and dancing; and with scenery, costumes and spectacle.

Generally, a musical is in two acts, of which the second is shorter and brings back some of the melodies heard earlier. Traditionally, the songs consisted of an introductory section (called the verse) and a main section (called the chorus) in A A B A form (32 bars). Hit tunes from musicals, like Ol’ Man River (from Showboat) or Some Enchanted Evening (from South Pacific), have often had lasting appeal, detached from their original theatrical context.

The American Musical embraces a variety of styles, yet it is a distinct type of musical theatre, separate from opera. In contrast to opera, it tends to use simpler harmonies, melodies and forms, and it contains more spoken dialogue. Its songs tend to be narrower in pitch range than operatic arias because popular singers and opera singers have different vocal techniques. Also, the musical is even more of a collaborative effort. In opera, one composer writes and orchestrates the music, and one librettist – occasionally two – is responsible for the entire text. In a musical, one composer creates the songs, but other musicians are responsible for the orchestration, the overture, the connective musical passages, and the music accompanying dances. The spoken dialogue and song lyrics are usually divided among two or more writers. Despite these differences between musicals and operas, certain works, such as George and Ira Gershwin’s Porgy and Bess (1935), fall somewhere between the two categories. Shows originally produced as musicals, like Porgy and Bess and West Side Story, are sometimes performed later in opera houses and recorded by opera singers.