Prog is based on fusions of styles, approaches and genres, involving a continuous move between formalism and eclecticism. Due to its historical reception, prog's scope is sometimes limited to a stereotype of long solos, long albums, fantasy lyrics, grandiose stage sets and costumes, and an obsessive dedication to technical skill. While the genre is often cited for its merging of high culture and low culture, few artists incorporated literal classical themes in their work to any great degree, and only a handful of groups purposely emulated or referenced classical music.