Benedict Mason, 50 next year, has gone through several transformations during his career. The fine orchestral piece The Lighthouses of England and Wales (1988) established him, but the last time Mason grabbed the headlines was with his football opera Playing Away, staged by Opera North in 1994. Since then, Mason has lived mostly in Paris and concentrated on site-specific works, none of which have made it across the Channel.

Even his early music remains little known over here. ChaplinOperas (1988) has been heard in London before, at the South Bank's Meltdown festival a few years ago, but went almost unnoticed. This performance by the London Sinfonietta, conducted by Franck Ollu, attracted much more attention. Although Mason's idea of writing scores to be played during screenings of three of Charlie Chaplin's shorts from 1916 and 1917 might seem commonplace, the results are anything but.

Mason uses Chaplin's wonderfully choreographed comic fables (Easy Street, The Immigrant and The Adventurer) as the skeleton around which he constructs his complex webs of sounds and words. Two singers, a mezzo and a baritone (Della Jones and Omar Ebrahim in this performance), deliver a range of texts that tease out the implications of the action. Mason's scores are similarly allusive. There is some directly illustrative writing, tightly coordinated to the images, alongside elaborate textures stuffed with quotations. He makes marvellous use of snatches of Debussy's La Mer and Verdi's Falstaff in The Adventurer, for instance, as well as Ivesian collages of popular tunes, brassy riffs and rhythms.

It's virtuoso stuff, fabulously well played by the Sinfonietta, although perhaps a lot to take in for a single performance. The words were hard to decipher in the QEH, and the musical elements of the first two films are rather too similar when heard back to back. But the treatment of the third, The Adventurer, is magnificent - as rich, inspiring and funny as Mason intended.