Gwyn Pritchard: Nephalauxis
string quartet and 2 percussionists (1977)

In 1971 I wrote a piece for the same combination and with the same title, but later, having serious reservations about it, withdrew the work. Nonetheless, the basic idea continued to hold a persistent fascination for me, and as I felt that certain elements were worth preserving, some time later, in 1977, I decided to rewrite it completely.

This basic idea is contained within the title Nephalauxis meaning an expanding cloud. The term "nephalauxetic" is used in chemistry to describe a theoretical concept; however my piece does not attempt any sort of literal translation of the scientific concept in musical terms, but explores the idea of progressive expansion to the point of self-annihilation. This is a relatively simple piece - accordingly, its technical processes are also very straight-forward. A short fragment played on the viola in the twelfth bar is systematically expanded at each reappearance by the addition of certain intervals. At certain strategic moments the expanded note series is compressed and the process of expansion begins over again. This procedure is contrasted by the periodic appearance of certain unchanging elements: a sustained note G, short rhythmic figure played on the claves, and three chords built on a mirror structure. Near the end a gong stroke ends the expansion process, leaving only these unchanging elements and the original viola figure. The final mirror chord uses notes both higher and lower than anywhere else in the piece.

Nephalauxis was first performed at the Warsaw Aurumn Festival of 1979 by the Royal Lazienki Quartet with the percussionists Marta Ptaszynska and Hubert Rutkowski.