This disc, devoted exclusively to Kurtág's music for string quartet, is of great significance, and both performance and recording are equal to the enterprise. The Keller Quartet have secure technique as well as emotional commitment, while ECM has provided a warm yet spacious acoustic for this expressive music. The journey begins with Kurtág's Op 1 of 1959, in a world, dominated by expressionistic fragmentation, of which he's clearly the master. Eighteen years later, in the Op 13 Microludes, Kurtág has perfected his own personal style, in which small, separate forms are linked together, and the music's allusions – to Bartók and Webern, in particular – are subsumed into a lyrical, dramatic discourse. The fruits of Kurtág's long apprenticeship are most evident here in the superb Officium breve of 1988-9, a miracle of textural imagination and musical thought whose richly varied language is distilled further into the two miniatures – Ligatura (also 1989) and Aus derFerne (1991). By now Kurtág's music is characterised by a concentrated homogeneity, and by a harmony whose tensions, and stability, are the result of bringing convergence and divergence into confrontation. The result is memorable, and these fine recordings provide immensely rewarding listening.