Diferencas was an old Spanish naming of musical compositions dealing with various techniques involving theme and variation. In modern Spanish it simply means differences. It’s a nice title, however, and as to the present piece, a very fitting one indeed, because I wrote it especially to The Elsinore Players for their South America-tour in 1981.
Actually nothing happens to the clipping of wellknown Bach (the first four bars of the chorale: Jesu, Joy of Man’s Desiring, cantata No. 147), apart from the continuous changing of the succession-pattern of the 11 triplets and one duplet, the latter of which creates the recognizable 8/8 pattern amidst the flow of 9/8 "spinnrad-rolling". To put it popularly, I haven’t included anything that Bach does not have in the book himself.
In addition to that, the unpredictable accents and various instrumental colours are the only means of "differences". There are no modulations, no tricky polyphony, nothing but a long, thoughtful tasting the beautiful piece of tune. Well, of course, the chorale itself enters the picture in the very last section, but that is merely for me to have the pleasure of tossing it away again before it comes to a proper end.
- Poul Ruders