Van Dyke Parks with Britten Sinfonia and special guests Robin Pecknold, Daniel Rossen and Gaby Moren, Barbican, London

I'd been minded to introduce the music of Van Dyke Parks as 'eclectic.' A musical prodigy and child actor starring alongside Hollywood greats from Grace Kelly to Alec Guinness, he later became pals with Brian Wilson and co-wrote the recently resuscitated Smile.

As an arranger, the 69-year-old American's back catalogue veers from Disney's The Jungle Book to Joanna Newsom's opus Ys. His late Sixties/early Seventies albums, the just re-released Song Cycle, Discover America and Clang of the Yankee Reaper, take in folk, blues, pop, jazz - oh everything, from vaudeville music hall to Golden Age musicals, Caribbean Calypso to children's ditties...

But Parks anticipates this tag: “a rock journalist might call it 'eclectic'... I call it natural,” he states, explaining he's simply – naturally - influenced by whatever he hears.

In the end, the evening is less eclectic than expected. The presence of the Britten Sinfonia smooths out the styles – so the Calypso of 'FDR In Trinidad' is diluted, while strings and flutes lushly augment the brassy groove of 'Riverboat' or 'Death Don't Have No Mercy''s classic blues.

Where it comes together best are on tracks that cry out for a big Hollywood show time vibe anyway - for Parks is a shameless showman, practically jazz hands-ing when not tinkling the ivories. Randy Newman's 'Vine Street' going into Parks' 'Palm Desert' are flamboyantly delivered with shuffling drums, sweeping strings, romantic harp. Elsewhere, Parks' gregarious good humour is catching, and it seems almost, well, natural that there should be three sprightly tracks inspired by the tales of Uncle Remus. But forget Brer Rabbit – 'Opportunity for Two' has me channelling Thumper when it comes to toe-tapping.

Parks is a revered figure for musos, and has three special guests to prove it - Guatemalan singer Gaby Moreno, Robin Pecknold of Fleet Foxes and Daniel Rossen of Grizzly Bear. The latter pair shyly shuffle like schoolboys shown favour by a master; Parks seems almost amused, if pleased, by their presence. But while their names will no doubt have pulled in a whole new audience tonight, they are woefully under-used, their vocal harmonising rarely heard over Parks' less pretty but more strident vocals.

Not that this stops the audience exhibiting similar adoration for Parks come the encore: Smile's 'Heroes and Villains' is predictably popular, and when he gets down on one knee at the end of 'Another Dream', they meet him by rising to their feet.