Emerson, Lake & Palmer (ELP) were an English progressive rock supergroup formed in London in April 1970. The band consisted of Keith Emerson (keyboards), Greg Lake (vocals, bass, guitar and producer) and Carl Palmer (drums and percussion). With nine RIAA-certified gold record albums in the US, and an estimated 48 million records sold worldwide, they were one of the most popular and commercially successful progressive rock bands in the 1970s, with a musical sound including adaptations of classical music with jazz and symphonic rock elements, dominated by Emerson's flamboyant use of the Hammond organ, Moog synthesizer, and piano (although Lake wrote several acoustic songs for the group).