The styles of Broadway musicals reflect the history of the genre. The modern musical era began with the book musical, in which the songs and dances are used to further the plot. Musicals began to incorporate rock influences in the 1960s, a development reflected in today's jukebox musicals. Other influential styles are seen in the romantic mega-musicals of Andrew Lloyd Webber and the more intellectual and intricately crafted works of Stephen Sondheim.
Book Musicals
In book musicals, songs and dances further the plot and reveal character motivation and choices, rather than just providing musical entertainment. The quintessential creators of the traditional book musical are Richard Rodgers and Oscar Hammerstein, who broke new ground in the musical theatre world with the premiere of "Oklahoma!" in 1943. Rodgers and Hammerstein's musicals were also ground-breaking because of their willingness to take on social issues.
Often considered the top lyricist and composer working in modern musical theatre, Stephen Sondheim is lauded for his intricate compositions and complex lyrics, and has moved the book musical into new territory. His songs are written to express the thoughts and emotions of the character singing, and are usually psychologically and lyrically complex to an extent not seen with other lyricists.
The music and songs of book musicals tend to alternate between dramatic, emotional ballads and sprightly dance or humor numbers. Orchestrations are traditional, utilizing a full acoustic orchestra.
Rock and Jukebox Musicals
Broadway musicals moved into a modern era with the debut of "Hair" by James Rado, Gerome Ragni, and Galt MacDermot in 1968. Other notable rock musicals include "Godspell," "Little Shop of Horrors" and "Rent," all of which debuted off-Broadway but influenced the Broadway scene significantly.
Rock musicals are similar to book musicals in that the songs continue to advance the plot, but different greatly in instrumentation and orchestration. Eschewing traditional orchestral instruments, rock musicals instead draw their sound from rock music, using electric instruments and standard rock drum kits.
A variation on rock musicals is the jukebox musical, which draws from the works of one artist (such as ABBA with "Mamma Mia!," The Four Seasons with "Jersey Boys" and Green Day with "American Idiot"), typically in a rock genre. Jukebox musicals differ from rock musicals, however, in that their songs usually do not further the plot, but are sung by performers on a stage-within-a-stage.
The Mega-Musicals of Andrew Lloyd Webber and Others
The mega-musicals of the 1980s and later are distinguished as much by their lavish special effects and scope as much as by their music. Andrew Lloyd Webber's "The Phantom of the Opera" with its falling chandelier became the longest-running musical on Broadway, and opened the door for similar mega-musicals, including "Les Miserables" and "Miss Saigon" by the French team of Claude-Michel Schoenberg and Alain Boublil, as well as other hits by Lloyd Webber.
Mega-musicals represent a step away from the modernization of the Broadway musical that began with "Hair" and other rock musicals, with their return to traditional orchestras and romantic orchestrations.