BBC Symphony Orchestra, John Wilson, Barbican

Erich Korngold was up first, the father of Hollywood composition. Wilson, a suave Geordie, dressed as if he'd just shimmied off the set of Mad Men, compering as well as conducting throughout the evening, recalled Previn's line on Korngold. When Korngold's music was accused of having the whiff of Hollywood, Previn quipped that, quite the contrary, it was Hollywood that had begun to whiff of Korngold.

The glorious main title of the Ronald Reagan-starring film Kings Row was as regal as you could get. Erected on the most magnificent brass columns, the melody, with its resplendent triplet descent echoing "Glück das mir verblieb" from Die Tote Stadt, returns and returns and returns again. Why was such a richly, royally upholstered score demanded for a film about small-town American life? Because Korngold hadn't seen the movie before writing the music.

If some of the works on the programme conveyed a bare-boned simplicity and clarity of purpose it is all to do with the demands of the films and not the quality of the music composed, which was all top drawer. Some of it, however, was deliberately second-hand. Miklós Rózsa's Waltz for Vincente Minnelli's Madame Bovary (1949) was supposed to sound like Ravel's La Valse - and it did a little too much for me. Conversely Franz Waxman's suite to Prince Valiant (1954) was very like second-hand but first-rate Richard Strauss - though I'd far prefer to ride with the rainbow colours and lush melodies of this work than with some of those more granite-faced tone poems.

Some of the works were begging for John Wilson's own orchestra to sweep us along. The BBC Symphony Orchestra did a good job for much of the time but lacked a bit of rhythmic suppleness in the dancier and jiggier numbers such as Bronisław Kaper's Rite of Spring-pastiche for Mutiny on the Bounty (1962).

Mostly enjoyment flowed as freely as the major chords. So many of these sounds - the swooning strings, the belting brass, the river-running harps - hardly ever get an airing in classical concerts, and certainly not in this family-friendly, un-ironised form. We aren't supposed to take these 1950s Hollywood scenarios seriously. Slowly but surely the postmodern cages in which the 1940s and 1950s have been imprisoned are being prised open. Mad Men is a product of this. In the high-minded world of music it is riskier to take the plunge, lest one is tagged as tacky. (It's still bizarre that it will be easier for me to find scores by a 15th-century Occitan troubadour in my local library than it would be to find Hollywood's finest offerings.)

John Wilson - whose detective work has reconstructed many of these unarchived movie scores - is pioneering the recovery, presenting these works with all the seriousness that they deserve. Cole Porter's music to Rouben Mamoulian's Silk Stockings (1957) is an extraordinary slow, moody, slinky rumba, pouted out on an alto flute with a playful cello accompaniment. Hearing the gay and Copland-esque suite to The Wizard of Oz (1939) by Harold Arlen and Herbert Stothart in concert with the BBC Chorus "oohing" and "aahing" like a sea of mermaids reminded me of Daphnis et Chloé every now and again. Most vivid were the soft numbers from David Raksin in his suite for The Bad and the Beautiful (1951), the music rising dozily like steam off a hot bath, and Newman's conjuring-up of the sublime in his suite for The Song of Bernadette (1943) with soprano voices and an earthquakey bass.

Bernard Herrmann in this context was a bit out of place, so psychologically and musically advanced was his Eisensteinian cut-and-splice compositional style - a chunk of arpeggios, a chunk of strings, a chunk of brass and repeat - in the selection of cues that we got from North by Northwest (1959). But for the finale we were back to Hollywood sweep and the unwaveringly grandiloquent swellings of Max Steiner's blowy score to Gone with the Wind (1939).

John Wilson represents a turning of the tide of the post-war quest that has tried increasingly to ironise, complicate or sometimes even simply ignore high and late-Romantic music. Next, he should be let loose on the likes of Bruckner, Mahler and Strauss, where he can start to reinstate the Hollywood-like adventures and melodrama that have been intellectualised out of their works.