CLASSICAL MUSIC American Independents SBC, London

The second stage of the "American Independents" festival was an eight-hour marathon last Saturday: an RFH foyer programme by the expert South Bank Gamelan Players, followed by three concerts all featuring London Sinfonietta musicians, plus an illuminating conversation between John Adams and Natalie Wheen.

The festival is offering several opportunities to reassess composers either problematic or just inadequately known. At almost 80, Lou Harrison is the USA's senior experimentalist. His Mark Twain on the Philippine War for Gamelan and its own singers and, in particular, Concerto in Slendro for solo violin and five keyboard and percussion players had some nicely imagined textures. But it was still hard not to level the usual charges against this composer: too much reliance on non-Western sounds and insufficient real individuality.

Adams - conductor of the main evening concert - reveals that when Frank Zappa sent him some of his own ensemble music in the late 1970s, he failed to "get it". I still have trouble "getting" works such as Dupree's Paradise and The Perfect Stranger: they seem too much like a series of random, often brutal, occasionally vivid, responses to the little stories that apparently propel them than music of substance or lasting consequence. But Ruth Crawford Seeger's Three Chants for Women's Chorus of 1930 conjures original and convincing things out of the combination of a "magical Eastern language" and some highly dissonant, textural materials, seeming at least 30 years ahead of its time. Morton Feldman's highly evocative Rothko Chapel was, despite Paul Silverthorne's occasional over-indulgence of vibrato in the important viola solos, a moving conclusion to the whole evening.

There were three recent works by Adams himself. Road Movies for violin and piano consists of three only intermittently engaging movements lacking this composer's usual aplomb and melodic fecundity; but Clio Gould and John Constable's somewhat cautious performance was partly to blame. Divested of their context, five numbers from the rock-orientated music-theatre work, I Was Looking at the Ceiling and Then I Saw the Sky, seemed merely curious exercises, even for a composer who believes we live in "post-stylistic" times.

Most rewarding was the first performance of Gnarly Buttons, a three- movement clarinet concerto, vivaciously played by Michael Collins and the Sinfonietta under the composer. It's a typical Adams, from its homespun title ("gnarly" means "awesome" as well as knotted) to its "forgery" of music models: a Protestant hymn, a hoe-down, a love song. Among expected delights is a brilliant use of an ensemble consisting of cor anglais and bassoon, a banjo / mandolin / guitar player, trombone, two keyboard players and strings. But Gnarly Buttons is much more than a clever "wheeze": the way the first movement unfolds its expanding single line, for instance, demonstrates a control of timing as well as texture, of chromatic inflection as well as the drama of more familiar solutions. Masterly.