The leader of Jethro Tull occasionally records a solo album that departs significantly from the output of his group (although it can be argued that every Tull album since the mid-'70s has, in effect, been an Anderson solo project supported by whatever musicians he chooses to call "Jethro Tull"). His solo material tends to be more overtly serious, and more oriented toward instrumental music than Tull's music. . The leader of Jethro Tull occasionally records a solo album that departs significantly from the output of his group (although it can be argued that every Tull album since the mid-'70s has, in effect, been an Anderson solo project supported by whatever musicians he chooses to call "Jethro Tull"). His solo material tends to be more overtly serious, and more oriented toward instrumental music than Tull's music.