Proms BENEDICT MASON, MALCOLM WILLIAMSON: PREMIERES Royal Albert Hall, London

Should composers be banned from writing their own programme notes? Some can write entertainingly, it's true, and on occasions one of them actually says something helpful, but mostly they fail to address the basic question: how should the audience approach their work?

Benedict Mason, writing about his Clarinet Concerto in Wednesday's Prom, could only tell us with any clarity what his piece wasn't - that it avoided spurious concepts such as "musicky" or "composerly" writing. Malcolm Williamson, introducing his A Year of Birds in Saturday's programme-book, waffled delightfully, scattering names of artists and thinkers like confetti, and reaching a startling climax with the suggestion that Olivier Messiaen invented not birdsong, but God.

In the end there was nothing for it but to take each piece as it came. Williamson's "symphonic song-cycle" set 12 poems about birds by Dame Iris Murdoch. The three parts were virtually identical in form: songs alternating with interludes. The orchestral interludes were often energetic and harmonically astringent, while the songs themselves were in Williamson's Puccinian vein: warmly, sweetly tonal and very much melody-led, though with a faintly clashing counterpoint of bird imitations.

These two styles often sat uneasily together. Was that Williamson's intention? From this performance, by the BBC Concert Orchestra under Barry Wordsworth, it wasn't easy to say. But even though soprano Alison Hagley sometimes sounded rather small in the midst of the vast Albert Hall spaces and Williamson's ripe orchestration, the songs themselves could be quite gorgeous. Few composers today write singing, romantic lines as generously as Williamson. I couldn't help wishing that he'd surrendered completely to his lyrical side and allowed himself to forget that he's a late-20th century composer.

Mason's Clarinet Concerto could have been composed as a negation of everything in Williamson's piece. There were no lines, no expression, no harmonic sense - only little blobs of instrumental colour from the soloist, with answering sounds from invisible players outside the auditorium. For 10 minutes or so it was weirdly fascinating, then the refusal to do or say anything became a form of torture - like being cornered by a bore who knows the effect he's having and is enjoying every moment. Serves you right for being "musicky".

But there were things in this late-evening London Sinfonietta Prom which showed that music still lives. There was Julian Anderson's wild, densely written but very exciting dance suite Khorovod. And while Ligeti's Melodien and Conlon Nancarrow's Studies for Player Piano (Pianola) are products of another age, they still point to musical paths that have hardly been trodden. Markus Stenz didn't quite seem to have the measure of the Ligeti, but Nancarrow's Seventh Study, arranged by Ivar Mikhashoff, was exhilarating and manically funny, and the energy of the playing in Khorovod brought Julian Anderson a respectable-sounding cheer even from this . . . let's say "select" audience.