Here's a challenging solo arrangement, along with an accessible ensemble version, of one of Bach's organ masterpieces. Surprisingly, apart from the transposition from Eb to the more guitar-friendly D major, the arrangement is almost entirely faithful to the original.
A clean text is provided first, followed by a version with fingering, then a version with the three parts presented in open score. This can be tackled in many ways - three guitars, or doubled in a guitar ensemble, as a duet (with a melody instrument taking either the top line or the chorale melody in the middle part) or with a mixed group (try pizzicato cello or bass for the bass line).