The most significant musical news event of 1984: On Dec. 18, Christoph Wolff, chairman of the music department at Harvard University, announced he had discovered 33 previously unknown chorale preludes by Johann Sebastian Bach.

It was not the only such discovery this year; a long-forgotten opera by Donizetti was unearthed, and the last song composed by Richard Strauss was found and sold at auction for $61,000. But the magnitude of the Bach find makes it one of the century's most significant.

In Washington, the major news in music hinged on a number: $20 million. That is the goal of a fund drive launched by the National Symphony Orchestra to raise the level of its endowment. Remarkably, the drive began halfway to its goal, with more than $9 million pledged by members of the NSO board, $125,000 pledged by two national trustees and a $900,000 challenge grant from the National Endowment for the Arts. The Washington Opera is rumored to be planning a similar campaign, with somewhat smaller figures involved, to be announced next year.

The need for financial support was felt more than usual this year. Ticket sales were generally down in Washington, perhaps because it was an election year. The National Symphony may have lost some ticket sales because the entire year passed without music director Mstislav Rostropovich conducting a single subscription concert. He took a sabbatical year for several purposes -- among them, reexamining the Bach suites for unaccompanied cello, which he plans to record. He played some of this music in Washington, at two benefit concerts, and he conducted the Catholic University Orchestra and Chorus at Constitution Hall. He also conducted the National Symphony on a South American tour, but his only appearance with the NSO in Washington was at the Fourth of July concert on the Capitol grounds. His costar on that occasion was James Galway, whom Rostropovich jokingly called a "rock star." The enormous audience's reaction justified that description.

While Rostropovich was out of town, his wife, soprano Galina Vishnevskaya, published her autobiography, "Galina" (Harcourt Brace Jovanovich), the year's most spectacular book about music for a general readership. Two other books deserve special mention: "The New Grove Dictionary of Musical Instruments" (Macmillan, three volumes) is the most distinguished music publication of the year; "The Glenn Gould Reader" (Knopf) is the most stimulating.

In Rostropovich's absence, the most notable musician resident in Washington was Daniel Barenboim, who conducted "The Marriage of Figaro" for the Washington Opera and played Beethoven and Brahms concertos with the National Symphony. The NSO was host to an unusual number of guest conductors, whose varied styles served as a showcase of the orchestra's growing versatility and its improvement in recent years. Among them, Michael Tilson Thomas received a particularly warm critical reception. Charles Dutoit, who has become well known on records, conducted two programs with less impact -- some excellent moments, but many others that seemed underrehearsed. Andrew Litton, who has been the orchestra's Exxon/Arts Endowment conductor for two years, conducting youth and pops concerts, made an auspicious debut in the subscription series. But the orchestra's most spectacular success of the season was Verdi's Requiem, conducted by principal guest conductor Rafael Fru hbeck de Burgos.

The Washington Opera, following closely behind the New York City Opera, introduced the use of surtitles for its foreign-language productions in the Opera House (there are still technical problems in the Terrace Theater). This innovation involves the projection of a translation of the opera's text on a screen above the stage. Audience reaction was overwhelmingly -- but not unanimously -- favorable.

The Filene Center at Wolf Trap, destroyed by fire two years ago, reopened with a gala performance featuring Placido Domingo. One notable event of its short season was a performance of Beethoven's Ninth Symphony with Hugh Wolff conducting the National Symphony Orchestra. The other performing facility at Wolf Trap, The Barns, continued to present music throughout the period during which the Filene Center was closed, but the general public seems still unaware of its acoustic quality -- perhaps even of its existence. Another relatively new and small auditorium, the Kennedy Center's Terrace Theater, finally found its audience after five years of operation. Chamber music programs there began to sell out regularly this season, although vocal recitals and the imaginative programs of the Theater Chamber Players still play to some empty seats.

In general, serious music in America continued to move in the direction of Neoromanticism: accessibility, lyricism and the expression of feeling as opposed to the making of relatively abstract structures. The trend was confirmed yet again at the Kennedy Center/Friedheim Competition, which awards prizes each year for new American music.

The Metropolitan Opera, celebrating its 100th anniversary, brought to Washington the most distinguished series of productions it has taken on the road in many years. The singers were from the top of its roster (not the usual practice in past tours), including Placido Domingo, Jon Vickers, Johanna Meier, Marilyn Horne and Renata Scotto. Music director James Levine chose Washington for his first staged performance of an opera from Wagner's "Ring" cycle, "Die Walku re," with results that augur well for his further efforts in this repertoire. Also notable was the production of Handel's "Rodrigo," the first Handel opera ever performed by the Met and one full of spectacular singing and stage effects.

The Met's neighbor, the New York City Opera, made a strong comeback after an orchestra strike last year that threatened to put it out of business. In a season that ran through the summer and into early November, it showed its usual flair for innovative programming with titles that included "Akhnaten" by Philip Glass, an operatic production of Sondheim's "Sweeney Todd" and a "Carmen" set in the period of the Spanish Civil War. This "Carmen," later televised on PBS, was one of the most effective operas shown on television this year, though it was surpassed by the Met's lavish and superbly cast "Don Carlo" (now available for home video on a Pioneer Artists LaserDisc.) The City Opera has not played in Washington for several seasons because of the destruction of the Filene Center and its financial problems. It is reportedly planning to return to Wolf Trap in June.

"Carmen" was also the subject of the year's major operatic movie, starring Domingo and Julia Migenes-Johnson, an American singer popular in Europe but relatively unknown at home. The other major movie of the year involving classical music was "Amadeus" -- a powerful, intricate study of God's inscrutability and of the difference between genius and competence, greatly enriched by a sound track full of Mozart's music.

The major operatic controversy of the year was triggered by modern-dress productions of "Rigoletto" with a cast of gangsters rather than Renaissance noblemen. There were two such productions in the United States. The first was given in Norfolk by the Virginia Opera. Later in the season, the English National Opera toured the United States (but not Washington) with the production that had given the Virginians the idea.

Compared with next year, 1984 had few notable musical anniversaries; the music community took a deep breath to prepare for the 300th anniversaries of the births of Bach and Handel. Other anniversaries: Domenico Scarlatti (also 300), Heinrich Schutz (400) and Alban Berg (100). We are already in the middle of the centennial year of Charles Tomlinson Griffes, which will run through next summer. But none of these is likely to attract a tenth of the attention coming to Bach and Handel.

The Handel anniversary was anticipated by the University of Maryland's annual Handel Festival, which presented a mammoth performance of "Messiah" at the Washington Cathedral, conducted by Antal Dorati and using hundreds of performers, including an orchestra of 100 playing on antique instruments. At the Cathedral earlier in the year, Leonard Bernstein conducted a memorable performance of Mahler's Second Symphony as a protest against the arms race. Less memorable was the production of his curiously hybrid opera, "Trouble in Tahiti" and "A Quiet Place" at the Kennedy Center. He also conducted the Vienna Philharmonic here in a performance of Mahler's Fourth Symphony that mingled elements of greatness and shameless self-indulgence.