The jazz pianist Jess Stacy, who died on New Year's Day in l995 at the age of 90, would have been surprised that anyone had deemed him worthy of a biography because the man who graced the big bands of Benny Goodman and Tommy Dorsey and Bob Crosby was rarely in the spotlight during the glory years of the Swing Era.

When Otis Ferguson wrote about Stacy in the New Republic back in l937 his piece was entitled Piano In The Band, stressing the self-effacing nature of the man who grew up in Cape Girardeau, a stopping-off point for the Mississippi riverboats in the early years of the century.

Now jazz collector Derek Coller has put together Stacy's story and discography in a book which he has titled Jess Stacy - The Quiet Man Of Jazz. The book tells of Stacy's career, of joining the Goodman band in l935 just as the Swing Era took off, of his troubles with Benny, his disastrous attempt to launch a big band of his own, and his eventual drop into obscurity when he moved to Los Angeles in the late forties.

It was entirely typical of Stacy's career that the exquisite solo he crafted during Goodman's historic Carnegie Hall Concert in New York in January 1938 was lost to posterity for a dozen years, hidden away on recording acetates in a cupboard at one of Goodman's homes.

The impact of that solo was enormous on the people who attended that ground-breaking event - no jazz group had ever been allowed in Carnegie Hall before that Sunday night. It was only when Goodman found the acetates - a friend had recorded the whole affair privately - that Columbia cleaned them up and issued the music and the rest of us could marvel at what Stacy did in that brief, two-minute-long solo.

In the book he explains: ''While we were playing Sing, Sing, Sing Benny seemed to like what I was doing behind his solo and, with no warning at all, he turned to me when he ended his chorus and said 'Take it, Jess'. I didn't know it was going to happen . . . and all of a sudden I was playing and that was all. I just kept on playing and years later I heard it on the record.''

It remains one of the great solos of jazz music and even listening to it today, 60 years later, it is a perfect little gem surfacing between the powerhouse trumpet playing of James and the wonderfully racketty drumming of Gene Krupa.

If that had been issued then Stacy's own career might have taken off.

Instead he remained the ''piano in the band'' with Teddy Wilson being featured so much more in the trio and quartet segments of the Goodman appearances.

He left Goodman 18 months later, spent a spell with Bob Crosby, returned to Goodman, and then joined Tommy Dorsey. Then, during the Second World War, he married singer Lee Wiley and started a big band of his own. It was a disaster because most of the best-known musicians were in the forces.

Interestingly, though, the Glasgow-born tenor saxophonist Benny Winestone ended up in Toronto spend some months with the band. In July 1945 Melody Maker reported in London: ''Benny Winestone, now a familiar figure around every New York bandstand, and a friend of hundreds of New York jazzmen, has been in rehearsal with Jess Stacy's new orchestra with which Mrs Stacy (Lee Wiley) will probably be featured. This is Benny's first US job since his arrival here from Canada. He still has a broad Glasgow accent.''

It won't surprise anyone who has heard the legend of Benny Winestone that the book adds that he was ''an illegal immigrant'' and soon returned to Canada! Essentially Stacy never fully reaped the benefits of his Swing Era days. He had frequent spells with the Condon Mob and later in Bob Crosby reunions on the West Coast as he gradually slipped into obscurity. And his professional pride would not allow him to take part in Hollywood's Benny Goodman Story when he was offered only scale for salary. Stacy turned on his heel and walked away. He was persuaded to play at the Newport Festival in l974 and was also lured into the recording studios, but sadly Stacy's time had passed.

The recordings still have that unique sound he brought to the piano, distinctive and utterly unmistakable, but the approach was often tentative.

When he died it wasn't Goodman he mentioned on his death bed but Frank Teschemacher, the Chicago clarinettist who was killed in a road accident in 1932. It was Tesch he called out for, no doubt remembering their early days in Chicago.

n The book is available from New Orleans Music, 52 Jackson's Lane, London N6 5SX, for #31.50 - price includes postage and a CD of Stacy playing solo and also in a group with trombonist Jack Teagarden (unissued material).