New performance rights laws (in 1833 in the UK and 1856 in the US) required clear definitions of theater, music, and performance. Weighing litigation throughout the nineteenth century (involving songs by Henry Russell, Augustin Daly’s famous “railroad scene,” and music published by Thomas Boosey), courts defined drama as embodied human action and music primarily as melody. In cases involving Gilbert and Sullivan’s attempts to secure some US copyright for their works, courts then confronted these different definitions of music and drama within the British pair’s operettas. Ultimately, rather than accept the possibility of music drama as an integrated performance genre, courts retained the already established formal definitions of the two media, privileging drama over music and invalidating Gilbert and Sullivan’s legal claims.