In 1971 I wrote a piece called Koan for solo violin which was concerned with the perceptual effects of an absolutely linear and predictable formal process — involving a bowed tremolo progressing through a series of microtonal intervals on progressively higher pairs of strings. The first violin part in this Koan for string quartet is essentially the same as that earlier piece, but here the other instruments of the quartet are used to provide a harmonic context — and thus a harmonic “Meaning” — for each of those microtonal intervals, within a fairly complex, just tuning system. The resultant sonorities might be conceived as a complex “chord progression” on various different roots or fundamentals. Some of these sonorities will be quite familiar to the Western ear; others are rather more “exotic”. But they are all derived by a simple extrapolation from traditional harmonic relationships