“All Blues” is a jazz composition by Miles Davis first appearing on the influential 1959 album Kind of Blue. It is a 12 bar blues in 6/4; the chord sequence is that of a basic blues and made up entirely of 7th chords, with a ♭VI in the turnaround instead of just the usual V chord. In the song’s original key of G this chord is an E♭7.
The piece is made even more distinctive by the bass vamp that repeats through the whole piece, except when a V or ♭VI chord is reached (the 9th and 10th bars of a chorus). Further to this, there is a harmonically similar vamp that is played by the horns (the two saxophones in the case of Kind of Blue) at the beginning and then (usually) continued by the piano under any solos that take place. Each chorus is usually separated by a four-bar vamp which acts as an introduction to the next solo/chorus.