The keepers of clarinetist Benny Goodman's musical legacy on Monday unveiled a trove of performances by the King of Swing not previously available to collectors. A lilting, playful, swinging version of ``Sweet Georgia Brown,'' driven by Goodman's clarinet and spiced with a Zoot Sims saxophone solo, reverberated through a conference room of the Yale Club. The number was the first cut in a 50-minute recording released by Yale University and Musicmasters at a news conference in the club. Before now, that performance had been heard only by diners at the Rainbow Grill in Rockefeller Center in June 1967. It was part of 400 unreleased tapes Goodman bequeathed to Yale when he died two years ago. Yale music professor Harold E. Samuel said the new album is a sampler of the tapes in the Goodman archive. Future releases will be devoted wholly to particular playing dates or recording sessions. Samuel described the performances as ``a more spontaneous, relaxed Benny Goodman than you would find on many of his other recordings.'' Selections on the record include ``If I Had You'' from a 1955 gig at Basin Street East in 1955, ``Poor Butterfly'' at the 1958 Brussels World Fair and ``Cherokee,'' taped at Park Recording Co. in 1958 but never released. The album closes with a Fletcher Henderson arrangement of ``Blue Room,'' performed by a Goodman band that included drummer Louie Bellson and trumpeter Randy Sandke. ``I never stop being thrilled by this music,'' said Goodman's daughter, Rachel Edelson, who said she wants to make new generations aware of ``the scope of his contributions to the field of music.'' ``My children, at age 8 and 4, are learning it very very well,'' she said. ``Sometimes they complain about listening to it all the time, but I want them to know it, and I play it nonstop.'' She said that except for a scene in the 1938 movie ``Hollywood Hotel,'' no film exists of the quartet composed of Goodman, drummer Gene Krupa, pianist Teddy Wilson and vibraphonist Lionel Hampton, because moviemakers then would not show black and white players together. ``I knew about my father being the first white musician to have hired blacks, but I simply had not been aware of the level of resistance that he met and that he simply didn't care about,'' Mrs. Edelson said. Royalties from the new releases will pay the cost of maintaining the Goodman archive, which, in addition to the tapes, contain 1,500 arrangements, 5,000 photographs, scrapbooks and other memorabilia. Goodman died in 1986. Yale already has cataloged and indexed the arrangements, which Samuel said will be ``a boon to performers and scholars for generations to come.'' Preserving the tapes, dating from the 1950s, has been the first order of business, Samuel said. Most of the 1950s tapes are acetate and must preserved on sturdier digital stock. ``There might be only one playing left on some of the acetates, and that one playing has to be a transfer onto more permanent material,'' he said. Identifying the performances and choosing the best for commercial release is being done by Loren Schoenberg, an authority on Goodman's work. ``Goodman was a fantastic perfectionist, and we have an obligation to him not to release anything that he would not have released himself,'' said Samuel. The albums are being marketed in the three popular formats _ long playing record, tape cassette and compact disc.