English composer William Faulkes' arrangement of the tune to "A Mighty Fortress." I heard this piece on an organ dedication concert recording almost 20 years ago and searched for years to find the piece of music. I had given up looking and had a renewed interest about a year ago and found it published by Bardon Enterprises in Germany.
This is a great piece useful for a concert or especially an organ dedication program. It starts with the theme on principals and reeds, a short oboe solo accompanied on the Positif 8 & 4 flutes, and then followed by a peppy abstract section in the manuals and pedal on a plenum chorus with a mixture added later with snippets of the hymn-tune here and there.
An entire verse of the hymn comes next on various registrations for the phrases, Great 8' Principal, Recit Viola, Celeste, and Vox Humana, Recit 8' Trompette, Positif 8' Principal, Recit Viola & Celeste, Positif Salicional and Celeste with the rumble of the 32' Soubasse underneath.
Then it goes into a fugal section with Principals throughout and some mixtures. Finally it builds to almost full organ with reeds with the pedal complete with 32' flues carrying the melody followed by the manuals. A strain of Chamade trumpet is followed by an ultra-soft strain on the Salicional and Celeste, before finally ending on full organ with everything but the kitchen sink.
PS... Almost forgot. A friend told me recently that the music can be downloaded from the Eastman School of Music's website free of charge here...