"Cassandra's Dream Song" for solo flute, by British expatriate Brian Ferneyhough, is designed to be unplayable; the struggle is part of the composition. Ingrid Culliford took on the challenge over the weekend, and with delightful results. With double notes and key slaps, and singing while she played, Culliford made her instrument twang, pop and soar with an extraordinary range of textures. The work was among a number of solos and small ensembles featured by the British contemporary group Lontano in its performance at the Hirshhorn Museum Saturday night.

In Simon Bainbridge's "Music for Mel and Nora," the oboe, expertly played by Christopher O'Neal, tries to free itself from the persistent and hypnotic piano part, finally breaking into loud, fast and percussive repetition. It was a strong performance but with the ending slightly weakened by uneven repeated notes from pianist Shelagh Sutherland, though the problem might have been the piano.

Sutherland was impressive, however, in Steve Martland's "Kgakala" ("Distance") for piano, a moving musical picture of the vast and timeless African continent.

The program included the slow-paced "Driving Out the Death" by Elisabeth Lutyens and closed with Judith Weir's amusing and accessible "A Serbian Cabaret," in which the string players tell Serbo-Croatian folk tales of wayward wives and Turkish wars. Fine solo lines by cellist Gillian Thoday and violinist Sophie Langdon added to the enjoyment.