A rock musical is a musical theatre work with rock music. The genre of rock musical may overlap somewhat with album musicals, concept albums and song cycles, as they sometimes tell a story through the rock music, and some album musicals and concept albums become rock musicals. Notable examples of rock musicals include Hair, Grease, Rent, Spring Awakening, and Next to Normal. The Who's Tommy and other rock operas are sometimes presented on stage as a musical.
The rock musical became an important part of the musical theatre scene in the late 1960s with the hit show Hair. Styled "The American Tribal Love-Rock Musical," the anti-war free-love hippie-themed, nude-scened Hair premiered in 1967 as the first production staged at The Public Theater. It moved to Broadway in October 1968.Your Own Thing also opened in 1968 and featured a gender-switching version of William Shakespeare's Twelfth Night. However, the first musical to hint at what was to come had been the final edition of the Ziegfeld Follies in 1957. This production featured one rock and roll number, "The Juvenile Delinquent". The song was performed by fifty-year-old Billy De Wolfe. This was followed by another precursor to the rock musical, Bye Bye Birdie (1960)." Although rock and roll would have to wait for seven more years before returning to Broadway, these early, tentative infusions of rock into musical theatre paved the way for Hair and its progeny.