Rob's Essential Choice (or some such thing) was burbling in the background on my car radio when I heard a most unusual sound; Bach's Goldberg Variations (some of them anyway) being played rather idiosyncratically on an organ. This was an interesting experiment. The extract ended with a stop being pushed half in which made the chord go flat and die away like a wounded bagpipe. Whilst a lot of Bach is transcribable for other forces, he really did write idiomatically for the organ, and this was so alien to his 'organ style' it really made you sit up and listen.