M.U. – The Best of Jethro Tull, released in 1976, is the first proper greatest hits album by Jethro Tull. It spans the years 1969 to 1975. The earlier Living in the Past (1972) compilation mainly dealt with non-album material, but this album only features one previously unreleased song, "Rainbow Blues".
"M.U." in the album title stood for "Musician's Union",[4] which is probably a reference to the various musicians from different line-ups of the band appearing throughout the album.
It was later re-released as The Essential in 2003, with exactly the same song order, but a different album cover.
Track listing
Side one
"Teacher" (A, C, E, G, M) – 4:07 (alternative mix)
"Aqualung" (C, E, H, I, J) – 6:34 (alternative mix, including the song's opening guitar riff played twice - previous US edits of the song began three seconds later, with the second playing of the riff)
"Thick as a Brick Edit #1" (B, E, H, M, R) – 3:01 (The first three minutes of "Thick as a Brick, Part One")