A close friend of Ian Anderson since their teenage, Jeffrey Hammond was called to replace Glenn Cornick as bass player in 1971. He recorded 5 albums with Jethro Tull and left the band in 1975 to pursue a career as a painter. He's often credited as Jeffrey Hammond-Hammond because, curiously, his mother's name was also Hammond. He is also the Jeffrey quoted in 3 early Jethro Tull song titles.