American musical theatre refers to live theatrical productions in which the characters sing and speak as they tell a story. Most American theatre is written for Broadway, a network of 40 professional theatres in New York City. Thus, American musical theatre pieces are commonly called Broadway musicals. Once it has been performed on Broadway, the show is always referred to as a Broadway musical even if it is being performed by a touring company, regional theatre, community group or school.
A musical has three parts which are the book, music and lyrics. The book refers to the words that the characters say, while lyrics are words that the characters sing. The book and lyrics together are called the libretto. The lyrics and the music together are called the score. Usually, these parts are written by different people. For example, the music for Oklahoma was written by Richard Rogers and the book and lyrics were written by Oscar Hammerstein II.
Early American musical theatre had a strong European influence. In addition to European operettas, American musical theatre has roots in vaudeville and burlesque. After the turn of the 20th century, George M. Cohan wrote the first true American musicals. According to the website Theatre History, "Not only were the settings and characters of Cohan's musicals thoroughly American, but his dialogue, lyrics and melody were colloquial and native. The spirit of brashness, cocksureness, energy and chauvinism that pervaded the Cohan musicals were unmistakably American."
All American musical theatre was comedy until Hammerstein and Kern wrote a musical play, Show Boat, which had much more serious themes. Today, artists write both musical comedies and musical plays. Recent examples of musical comedies are Avenue Q and Spamalot while examples of more serious musical plays are Next to Normal and Spring Awakening.
Broadway musicals serve many purposes. Musicals are an artistic expression of the composer, lyricist, set designer, costumier, director, choreographer and actors. They offer unique forms of communication that entertain audiences. Some musicals challenge political or cultural assumptions. Certain musicals serve as a record of various time periods in American history. Musicals that are available for schools to perform can be used as educational tools.
The most famous and popular American musicals are performed on Broadway for years. For example, Cats opened on October 7, 1982 and closed on September 10, 2000. As of 2010, Playbill reported that the longest running shows in American musical theatre history include The Phantom of the Opera, Les Miserables, Chicago, Beauty and the Beast, Rent, The Lion King, Miss Saigon and 42nd Street.