Jethro Tull were a British rock group, formed in Luton, Bedfordshire, in December 1967. Initially playing experimental blues rock, they later incorporated elements of classical music, folk music, jazz, hard rock and art rock into their music. The band went through several personnel changes and has had more than 20 official members, but was always fronted by the vocals, acoustic guitar, and flute playing of Ian Anderson. Other important members included guitarist Martin Barre, who had been with the band since 1968 after replacing Mick Abrahams, drummer Doane Perry, and bassist Dave Pegg.
The group achieved commercial success in 1969 with the album Stand Up, which reached No. 1 in the UK charts, and toured regularly in the UK and the US. The musical style changed towards progressive rock with the albums Aqualung, Thick as a Brick and A Passion Play and folk rock with Songs from the Wood and Heavy Horses. Jethro Tull have sold over 60 million albums worldwide, with 11 gold and five platinum albums among them. They have been described by Rolling Stone as "one of the most commercially successful and eccentric progressive rock bands".