The fifth studio album by the English rock band, originally released in 1971. The album was developed from the aborted "Lifehouse" project, a multimedia rock opera written by the band's guitarist and main songwriter Pete Townshend as a follow-up to the band's 1969 album "Tommy". The album features the classic Who singles "Won't Get Fooled Again", "Baba O'Riley" and "Behind Blue Eyes", and is widely regarded as the band's finest record.