Yes are an English progressive rock band formed in London in 1968. Over the course of their career, the band has included more than twenty full-time members, with key figures such as vocalist Jon Anderson, bassist Chris Squire, guitarists Steve Howe and Trevor Rabin, drummers Bill Bruford and Alan White, and keyboardists Tony Kaye and Rick Wakeman. The band are widely regarded as pioneers of progressive rock and have incorporated elements of rock, pop, jazz, and classical music into their work.