Jethro Tull are a British rock band formed in Blackpool in 1967. Led by Ian Anderson - singer, flautist and principal songwriter - they built a sound that weaves together progressive rock, English folk and blues. Albums like Aqualung (1971) and Thick as a Brick (1972) made them one of the defining acts of 1970s rock; the band has sold an estimated 60 million records worldwide.