Sonorities Apart was written during the summer of 1992 at the request of Robert Bates, Stanford University's Assistant Organist. In keeping with some of the wonderful repertoire for the organ, it is a toccata-like piece that draws its energy and basic sound from an almost uninterrupted moto perpetuo type texture.
The title has two meanings: First, it is a comment on how I approached the composition of the piece: As composers we are so concerned nowadays with specifying and relying upon (for the delineation of the musical shape of a piece) the sonorities we are working with. Whilst this specification is possible with the organ, it is not very practical, given that not every organ sounds alike, even if they do have the same basic stops. As I wanted to write a piece that was performable on any three manual organ (with pedals) I had to eschew the usual compositional preoccupation with specific timbres, and concentrate instead on writing a piece that utilised generic organ sounds alone.
This leads to the second meaning of the title, which is closely connected to this fundamental problem of writing for the organ: When the piece was finished I realised that the notation was even closer to a kind of tablature than musical notation usually is, literally telling the player where to put his or her fingers, how long to keep them there for, and when to move on to the next note. No dynamics, no expression marks, and not even a completely faithful representation of pitch, given that registration effects octave transpositions (as well as sometimes creating other unnotated pitches). So, I had the feeling that in giving this piece to the organist I was in effect saying, "apart from the sonorities, here's the music". This is not something which I would be happy about when composing for any other instrument or ensemble, but with the organ it is almost a necessity that you leave these choices (or at least some of them) to the performer. Naturally, since finishing the piece I have worked more closely with Robert Bates and together we have arrived at a satisfactory and much more specific registration scheme. This scheme remains generic however, and so Sonorities Apart should be performable on any three manual instrument, as was my original intention.