Walter Zimmermann's music is hardly known in Britain. Born in 1949, he reacted against the prescriptions of the postwar avant garde in Germany, and he has remained a musical outsider ever since. The work of American experimentalists, especially Cage's music of the 1940s, gave Zimmermann his starting point, and he used the folk music of his native Franconia as his raw material in the cycle of pieces called Lokale Musik that made his name in the late 1970s; two versions of one of those pieces, 10 Fränkische Tänze, frame these discs of string music, which also contain the 23 Ritornellos, based upon William Blake's Songs of Innocence and Experience, and the 45-minute solo violin Die Sorge Geht über den Fluss. The musical means may change – another quartet piece, Keuper from 1980, explores tiny differences of tuning and temperament – but the pared-down, almost self-denying character of the music, with nothing rhetorical about it all, has remained constant.