Nightcap : The Unreleased Masters 1972-1991 (1993) is a Jethro Tull double CD album released on 22 November 1993 with older and previously unreleased material. The first CD contains material much of which would be re-recorded and re-arranged as their sixth album, A Passion Play, while the second CD has material from the mid-1970s to early 1990s. It was produced in limited quantities with proceeds going to charity.