With a pair of concerts and the first public screening of Tony Palmer's documentary about the composer, the South Bank has been hosting a mini Malcolm Arnold festival. The main orchestral concert was given by the London Philharmonic, which has been associated with his music since the 1940s, when Arnold was the orchestra's principal trumpet. Conducted by Vernon Handley, it made a worthy and beautifully presented tribute, showcasing all aspects of his orchestral output, including the film music Arnold produced so prolifically during the 1950s and 1960s.

There is sometimes a tendency to portray Arnold, now 83, as a kind of martyr - a hugely gifted composer who was ignored from the mid-1960s onwards, when the British musical establishment belatedly recognised the importance of modernism and its consequences. Those who were able to see an advance copy of Palmer's film said it presented a disturbingly tragic portrait, but of a personal tragedy (of alcoholism and mental instability) rather than a musical one, and that judgment was borne out by this concert.

There was plentiful evidence of Arnold's wonderful ear, but a less convincing case for the enduring quality of his musical invention. The comic overture Beckus the Dandipratt, which made Arnold's name in the 1940s is a rumbustious, brassy display of orchestral high spirits, but nothing more, while the suite from his score for The Inn of the Sixth Happiness certainly manages to parody Hollywood orchestral writing, with its effective wind and string doublings, but never puts a personal stamp on the style.

The "serious" music proved no more convincing. The Second Clarinet Concerto, played with jaw-dropping fluency by Julian Bliss, is a mixture of jazzy riffs (it was written in 1974 for Benny Goodman) and earth-bound melodies with a strange, unrooted episode in the slow movement that seems to belong to another musical world altogether. There are similar disjunctions in both the Philharmonic Concerto (composed for the LPO in 1976) and the Sixth Symphony (1967) - moments when the continuity seems to break down and no amount of circular, repetitive melodies can bridge the gaps; there's no sense of a real symphonist here nor, deep down, of a significant composer.