High Quality Content by WIKIPEDIA articles! Aqualung is the fourth studio album by the rock band Jethro Tull. Released in 1971, Aqualung, despite the band`s disapproval, is regarded as a concept album, featuring a central theme of "the distinction between religion and God". The album`s "dour musings on faith and religion" have marked it as "one of the most cerebral albums ever to reach millions of rock listeners".Aqualung`s success marked a turning point in the band`s career, with them going on to become a major radio and touring act.