Music preview: The RSNO, Nathanial Shilkret's Trombone Concerto

THE name Nathaniel (Nat) Shilkret might not be as familiar as, say, George Gershwin or Leonard Bernstein. But had you lived through and enjoyed the lighter side of music in early 20th century New York, his name would have been every bit as famous.

Shilkret, son of an Austrian immigrant family, was born in New York's Jewish quarter in 1889. As a boy, he would have roamed the same streets as Gershwin or Aaron Copland. He and his brothers grew up - encouraged by a father who played just about every instrument - to learn to play one from an early age. He became something of a child prodigy, touring from the age of seven as clarinet soloist with the New York Boys' Orchestra.

By his late teens and early 20s, Shilkret had performed with the New York Philharmonic under Gustav Mahler, played in the Metropolitan Opera orchestra, and had crossed the stylistic divide to find equal fulfilment in the more popular world of Sousa's famous Concert Band and Edwin Franco Goldman's Band.

By 1926 he was director of light music at the RCA Victor record company, conducting on a vast number of pioneering recordings (the 1929 premiere recording of Gershwin's An American in Paris, among them) that sold over 50 million copies in total in his lifetime. That's hardly surprising, when you consider that the artists who played under him ranged from Benny Goodman, Lionel Hampton, Glenn Miller and Artie Shaw, to Jascha Heifetz, Gershwin himself and such notable opera singers as Feodor Chaliapin and John McCormack. He mixed with, and had influence over, the pick of America's musical crop.

Shilkret's tireless career led him eventually in the 1930s to Hollywood and to writing film music, including some of the classic soundtracks for Laurel and Hardy. He was the ultimate crossover artist who never sat still long enough to be categorised.

Maybe that's why few of us have ever heard of him.

Until this weekend, that is, when the Royal Scottish National Orchestra, in its "Postcards from the Americas" programme, will feature Shilkret's Trombone Concerto, a work of classical guise and proportions written for the great band leader Tommy Dorsey that only came to light recently as a result of painstaking detective work by one of the RSNO's former trombonists, Bryan Free.

"I've always been a big band fanatic, and almost felt a bit of a failure not having got into jazz while I was working with the RSNO," says Free, who now, in his retirement, seeks every opportunity to pursue his true musical passion.

As a fellow trombonist, one of his great heroes had always been Tommy Dorsey. "When someone told me they had heard a recording of Dorsey playing a classical concerto by Shilkret, I knew I had to track it down." Thus began a search for the music that was to lead Free to New York, and contact with Shilkret's descendants.He discovered, for instance, that it was not unusual at the time for such great classical conductors as Eugene Ormandy or Leopold Stokowski to encourage collaborations with jazz players. "Artie Shaw got a classical concerto written for him, and it's likely that Tommy Dorsey saw such an opportunity as a good publicity ploy," Free suggests.

"It's often been assumed that Dorsey commissioned his concerto from Shilkret, but it was actually Stokowski who commissioned it."

It took Free many years to find a full version of the recording he was looking for - not from one complete source, but four partial recordings "gathered from all corners of the earth". Getting hold of the music, however, was another story. Contact with Shilkret's daughter Barbara was unfruitful. "I spoke to her, she was full of promises, but it led to nothing."

Then came a stroke of luck. Free got into conversation with an American pianist, who was over recording the Gershwin concerto with the RSNO and was an ardent enthusiast of Shilkret's music. "He promised to get in touch with the National Library of Congress as he was sure there was a reduced score of the Trombone Concerto.

"Eventually I got a letter from the composer's nephew, who told me he had started organising the Shilkret family archives," says Free. "I went to his flat in America, which was a complete Aladdin's cave, and found the score, which was in a terrible mess and full of mistakes." To make it performable, Free had a big job on his hands. "I had to reinstate the cadenza from a wind band version that was in much better shape." But he persisted, completed it, and found a fellow enthusiast in American trombonist Jim Pugh, who "badgered the New York Pops Orchestra" into performing it at New York's Carnegie Hall, the same hall in which the original 1945 premiere took place with Stokowski and the New York Philharmonic.

But Free's dream was always to have it performed by his own former orchestra, the RSNO, here in Scotland.

And on Friday in Edinburgh, and Glasgow on Saturday, that dream comes true as part of a concert of classics from the Americas that includes Bernstein's Symphonic Dances from West Side Story, Copland's El Salon Mexico and Ginastera's Four Dances from Estancia.

The soloist is the RSNO's brilliant young Faroese principal trombonist Dvur Juul Magnussen, and the conductor is Miguel Harth-Bedoya, the Peruvian-born music director of the Fort Worth Symphony Orchestra.

"If you like Gershwin, you'll like this piece," Free promises. "There are bits in the second movement that are straight out of Porgy and Bess. It's filled with references to foxtrot, waltz, spirituals and boogie woogie." Free's performing edition is now lodged in America's Library of Congress, and his detective work has played a significant role in generating a growing interest in Shikret's music, including plans to bring to fruition a 13-scene musical that has never yet seen the light of day.

"It's very much along the lines of West Side Story," says Free. Sounds like a composer we ought to be hearing more of.

• The RSNO will perform Nathanial Shilkret's Trombone Concerto at the Usher Hall in Edinburgh on 3 December and at Glasgow Royal Concert Hall on 4 December. Tel: [phone].