“A rock opera is a work of rock music that presents a storyline told over multiple parts, songs or sections in the manner of opera. A rock opera differs from a conventional rock album, which usually includes songs that are not unified by a common theme or narrative.

A rock opera tells a coherent story, and may involve songs performed as if sung by separate characters in a drama, as in classical opera. A rock opera may or may not be presented in a staged performance. In recorded form it can be similar to a concept album (of which it is a subset), though the latter may simply set a mood or maintain a theme.”