Harrison Birtwistle's new string quartet was given a much-anticipated UK premiere by the Arditti Quartet. The Tree of Strings takes its title from a poem by the Gaelic poet, Sorley Maclean, and it represents Birtwistle's first conscious allusion to the part played by Raasay, the island off the west coast of Scotland where Birtwistle lived in the 1970s, in his own creative journey.

There is an elemental beauty in the music that evokes enveloping mists and infinite skies, yet the sometimes austere nature belies its richness of metaphor. While the viola apparently instigates, it is the cello whose dark, baritone utterances most characterise the incisive writing and condition the emerging patterns. At the same time, it is impossible to ignore the theatricality of the setting: four empty chairs and music stands transcribe an arc well beyond the confines of the quartet's tight semi-circle. But because one is drawn back to the tensions within the group, it almost comes as a surprise when, eventually, the viola distances itself and takes up a new place. Violins follow, leaving the cello to reassert its distinctive voice. This process only serves to accentuate the centrality of the musical ideas, and when the players go off one by one, leaving the cello to make its unmistakably final statement, the essential drama of the quartet medium has been reinforced.

Birtwistle seemed to be saying that only time gives the perspective with which experience can begin to be understood, a reflection deepened by his arrangements of Bach, which prefaced his own work and those by Stravinsky and John Cage.