When the Metropolitan Opera opens its 60th season of Saturday afternoon broadcasts on Dec. 4 with a three-hour preview of its 20 radio productions for 1999-2000, there will be a new audience tuning in--the first radio audience the Met season has had in South America. Texaco, which has been sponsoring the broadcasts since 1940, has reached an agreement with Radio Cultura-FM in Brazil, where Texaco has been operating since 1915.

Brazil will become the 33rd country receiving the Met broadcasts, which go live to hundreds of stations in North America, Europe and Australia.

The highlight of the Met's season will be the world premiere of an opera based on F. Scott Fitzgerald's "The Great Gatsby." The opera, commissioned by the Met with a libretto and music by American John Harbison, will have its premiere in December and its first broadcast on Jan. 1. Also receiving their first Met broadcasts will be Franz Lehar's "The Merry Widow" on March 4, and Boito's "Mefistofele" on Feb. 19. Most of the broadcast season will be dedicated to such familiar works as "Tosca," "Lucia di Lammermoor," "La Traviata" and "Rigoletto." Less often heard material will conclude the season, including Debussy's "Pelleas et Melisande" on April 8 and Wagner's "Ring" cycle on March 25 and April 1, 15 and 22.

Texaco has cut back funding for the television broadcast season, which will have only two new productions, taped during the season just ended. To fill out the season, there will be a rebroadcast of "Der Rosenkavalier," originally videotaped in 1982. The new productions will be Tchaikovsky's "Queen of Spades," on Sept. 8, and Mozart's "Marriage of Figaro" in December.

Crossover and Over and Over: Wynton Marsalis has recorded--expertly and imaginatively--nearly all the classical music written for a trumpet soloist and some that was not, notably "The Flight of the Bumblebee" on "Classic Wynton" (Sony 60804). He has introduced more than one jazz fan to the joys of baroque music in a set of duets with soprano Kathleen Battle (Sony 46672), and trumpet solos on "In Gabriel's Garden" (Sony 66244).

Two new CDs take him in two new directions. "At the Octoroon Balls" (Sony 60979), performed by the Orion String Quartet and the Chamber Music Society of Lincoln Center, shows him as a skilled crossover composer, blending classical and jazz dance styles in a way that could have originated only in New Orleans. This disc includes a suite from "A Fiddler's Tale" (Sony 60765), which can be heard in its entirety on a simultaneously released CD that shows yet another Marsalis: a storyteller (composer and narrator) in words and music. The title echoes Stravinsky's "L'Histoire du Soldat," and there are similarities, not only in the combination of spoken words with illustrative music, but also in the story of a violin with supernatural overtones.

B&B: Beethoven and Brahms continue to make news, although one died in 1827, the other in 1897. Just when you think you have heard all the Beethoven that's worth hearing, along comes a new compact disc by Fleur de Son Classics (FDS 57931): Beethoven's Piano Trios in D, Op. 36, and in E-flat, Op. 38. These are not among the composer's canon of six trios for violin, cello and piano; they were transcribed by Beethoven from his Second Symphony and his Septet, Op. 20. As the New Arts Trio demonstrates in its smooth, idiomatic performances, the music works beautifully in this more intimate format. Those who know the originals will find in this music an intriguing blend of novelty and familiarity.

Brahms has just been accorded one of the most lavish tributes a composer can get: a book devoted marginally to his life and intensively to his works--actually the surviving works. This self-critical composer destroyed a lot more of his work than he saved. Published by Norton, "The Compleat Brahms" is exactly what its title promises: a collaboration of 30 musicians and scholars discussing his works, his conservative style, his obsession with Beethoven, his musical friendship and disagreements. The book's editor, Leon Botstein, is music director of the American Symphony Orchestra, editor of the Musical Quarterly and increasingly busy recording interesting, long-forgotten pieces of 19th-century music.

Collaboration: Want to contribute to a symphony? Composer Robert Kapilow is looking for ideas from the Washington community for his "DC Citypiece: Monuments at the Millennium," a work in progress that will be premiered by the National Symphony Orchestra on June 29, 2000, at the Kennedy Center. He has held four dialogues on the project and will have four more on Tuesday, Wednesday and Thursday, and others in upcoming months. There will also be on-air dialogues with studio audiences at National Public Radio, exhibits and participatory projects at the Corcoran Gallery and the Kreeger Museum, and a documentary film on the project. For more information, including times and locations for the dialogue sessions, phone 202-337-6144.

New New Grove: Nearly 20 years have passed since the New Grove Dictionary of Music and Musicians was published in 20 large, data-packed volumes. An updated New Grove Dictionary of Music and Musicians, Second Edition, has been in preparation for years and is scheduled to come off the presses late in 2000. This time it will be available for subscribers in an online edition as well as in print. Other Grove publications, the New Grove Dictionary of Opera and the Grove Dictionary of Art Online, are already available to Internet subscribers. More information and periodic progress reports are available at www.grovemusic.com and www.groveopera.com.

CAPTION: Johannes Brahms, the subject of a new book from Norton, "The Compleat Brahms."