AT the age of 10, the Austrian composer Erich Wolfgang Korngold performed some of his piano work for Mahler, who declared him a genius.

Richard Strauss praised the boy's "mastery of form, individuality of expression and command of harmony Korngold also had an inate understanding of the scherzo idiom.

Hardly surprisingly, considering this was Vienna, the young Korngold was compared with an earlier child prodigy with whom he also shared a name - Mozart.

Unlike Mozart, Korngold, who was born 100 years ago today, won two Academy Awards for his film scores. But in common with Mozart, he had a watchful, possessive parent. Julius Korngold, however, was neither a failed musician nor a music teacher, he was a leading critic famed for vicious reviews which created resentment, which at times backfired on his son.

Furthermore, Korngold Senior's views on music were notoriously conservative, indeed reactionary, particularly given that the period was full of exciting modernist expansion. Hostile to Schoenberg and the Second Viennese School serialists, Julius was intent on preserving his son from such influences. Aside from his obvious genius - by 13, the boy had already completed his superb Piano Trio, and his Piano Sonata No 2, having perfected his Piano Sonata No 1 more than a year earlier the young Korngold seems to have been a sophisticated character of wit and intelligence, well used to mixing socially in artistic circles and capable of humourously deflecting his interfering father's antics.

Musically, however, he was to remain committed to tonality. Consistently pushing chromatic harmony to limits beyond even Mahler's, Korngold never lost his love of melody and so his large, sweeping vision appeared suspended somewhere in a twilight zone of reactionary late Romanticism and the avant garde, which certainly interested him.

A gifted pianist, he used the piano as if, it were an orchestra: much of his symphonic work is dominated by such flamboyant use.

By the late 1920s Korngold, already the celebrated composer of operas such as Violanta (1916), Die Tote Stadt (1920) and his fourth and personal favourite work, Das Wunder der Heliane (1927), was as famous a figure in Vienna as Schoenberg. He had also married - against his father's wishes - and was supplementing his income by conducting the operettas of Johann Strauss. Returning to the sonata form in 1931 he composed the Piano Sonata No 3.

The emerging American film industry, meanwhile, was beginning to draw on European talent. In 1934 the theatre director Max Reinhardt invited Korngold to come to Hollywood and arrange the music - Mendelssohn's - for a film version of A Midsummer Night's Dream.

For the next four years, during which he won an Academy Award for his score for Anthony Adverse, Korngold and his family travelled between Vienna and Hollywood. By then other Jewish composers had already become refugees. Early in 1938 Hollywood had summoned him back from Vienna, asking him to compose a score for The Adventures of Robin Hood which would win him his second Oscar. In March, the Nazis marched into Vienna.

Anschluss, the German annexation of Austria, alerted Korngold to the dangers his homeland held for him as a Jew. He left Austria and, conscious now of going into an enforced exile vowed not to compose concert music until Hitler had been defeated.

By 1946, the year after his father's death, Korngold, despite his success as a composer of original film scores for The Private Lives Of Elizabeth And Essex, The Sea Hawk and Between The Worlds, had enough of Hollywood. The score for Deception was his farewell. Slightly ironically, that movie centres on a love triangle involving an egomaniac composer, his pupil, who is also his mistress, and her former lover, a cellist who has returned from a concentration camp. In addition to the score, Korngold also composed a short concert piece. It was a cello concerto which he later extended to become his Cello Concerto, Opus 37.

When asked why he was not renewing his contract with Warner Brothers, Korngold replied: "When I first came here I couldn't understand the dialogue. Now I can." But in truth his reasons were far more serious.

Aware he was in danger of remaining a Hollywood composer, Korngold, then 50 and suffering from heart trouble, was no longer the child prodigy who completed his superb Violin Sonata aged 15. He made a determined effort, to re-establish himself as a classical composer. It was not easy. When his Violin Concerto now considered akin to Barber's, if far closer to authentic post romanticism than the American - premiered in 1947, it was dismissed - as a "Hollywood" work.

Leaving the movie business proved far more difficult than Korngold had anticipated. Returning to Vienna in 1950 was a disappointment. He continued to work on his Symphony in F sharp, which he had begun in his mind in 1947 while recuperating from a heart attack. This big, almost angry work with its echoes of Richard Strauss, Bruckner and Mahler, was largely composed during 1951 and 1952 as he travelled Europe for performances of his operas. Die Kathrin, his fifth opera elicited 40 curtain calls, only to be ridiculed by critics as old fashioned. Unlike the public the music fraternity did not welcome his lush post Romantic textures and continued to dismiss him as a man who merely made music for the movies.

Never physically robust, Korngold had nevertheless, been drafted, and served briefly in 1917 towards the end of the first World War. Because of his poor, health he was appointed his regiment's musical director. He composed several marches, only one of which, predictably entitled Military March, was published. It is a lively, jaunty piece the pace of which surprised the commanding officer. It is said he queried Korngold on this. The composer is reputed to have replied: "Ah yes, Sir - but this is for the retreat."

The culminative effect of his several careers - as child prodigy, as composer of orchestra works, as opera composer and conducter, as writer of successful film scores and perhaps, above all, as a composer balanced between the tonal and chromatic - is that Korngold the writer of big works has long been as displaced artistically as he was displaced politically during the war.

AT the time of his death aged 60 in California on November 29th, 1957, a year after suffering a stroke, Korngold was in despair, fearing his work would fall into obscurity. For more than 20 years he was right. In 1975, Die Tote Stadt performed at the New York City Opera enjoyed an unexpected triumph, possibly assisted by Kempe's revival of Symphony in F sharp three years before.

It was the beginning of a slow revival, helped by the re-emergence of tonal and to some extent, neo Romantic idioms, which has finally led to the rediscovery of a composer who, although he never compromised his artistic integrity, became the victim of his Hollywood success.