Fourthy Blues in A major (5238 short) is a backing track to play along. It is based on a 12 bar blues chord progression with harmonic ornaments that are always a fourth higher. For example, the A major
chord briefly changes to the D major chord. And with the D major
chord, the accompaniment briefly changes to the G major chord,
also up a fourth. The harmonic ornamentation of the E major chord
is of course also the chord that is a fourth higher than E,
i.e. A major. But on the turn around, the E major chord plays
the entire bar without any further embellishment.