† This article was originally written in January 1973 and after many revisions and some excisions was given as a talk in Hans Keller's ‘In Short’ series. Some points have been expanded here, very much in the spirit of the original and only because I am now able to say more easily what I was trying to reach then. The Postscript, however, is a reaction to these old thoughts; it attempts, by relating them to recent compositional endaevours, to chart various shifts of position which I am begining to recognize are taking place.