At two marathon three-day recording sessions in December 1975 and October 1976, the finest group that pianist Keith Jarrett ever led (his quartet/quintet with tenor saxophonist Dewey Redman, bassist Charlie Haden, drummer Paul Motian and, on the first sessions, percussionist Guilherme Franco) recorded enough material for four memorable albums: Shades, Mysteries, Byablue and Bop-Be. This four-CD 1996 box set has the complete sessions, including 11 previously unreleased alternate takes. Jarrett's inside/outside music (his unisons with Redman had a unique sound) both held onto the tradition of chordal improvisation and were reminiscent of Ornette Coleman's earlier acoustic groups. There are a few brief exotic sound explorations, but most of the music (best shown on the opening "Shades of Jazz") extends the swinging tradition into complex areas that have yet to be fully explored by others. Continually fascinating music.