Happy birthday: Mstislav Rostropovich and Janos Starker will perform together for the first time on Sept. 14 at the University of Indiana, where Starker has taught since 1958. In careers that have put them in music's top echelons for more than four decades, they have not exactly been enemies, but their relationship has been one of polite remoteness. This was not surprising; they are recognized as the greatest cellists of their generation, perhaps the greatest since the heyday of Pablo Casals.

Both are superb masters of their instrument and attuned to the subtlest nuances of the cello repertoire, but sharply contrasted in personality and musical style. Starker is notable for the aristocratic reserve of his stage persona, Rostropovich for his exuberant enthusiasm and the massive bear hugs he bestows lavishly on friends and fellow musicians. These qualities are reflected in the way they play.

It remains to be seen whether Starker will receive (or would accept) a Rostropovich hug at the gala concert, which will celebrate Starker's 75th birthday. Rostropovich will conduct the Indiana University Philharmonic. Besides Starker, soloists will include fellow cellists Gary Hoffmann, Maria Kliegel and Tsuyoshi Tsutsumi, and violinist William Preucil.

Nicht Schuldig: Placido Domingo has mended his fences in Germany, paying up to avoid charges of tax evasion in the nick of time. The world-famous tenor and artistic director of the Washington Opera has had a career in German opera (notably Wagnerian roles) unusual for a Latin tenor and has two major recordings of German music scheduled for release between now and Christmas: Beethoven's "Fidelio" (from Teldec) and Mahler's "Das Lied von der Erde" (from Sony). German impresario Matthias Hoffmann, who produced a "Three Tenors" concert in Germany a few years ago, has been convicted of evading taxes on $8 million and sentenced to more than five years in prison.

Coming events: A benefit concert for victims of the Turkish earthquake will be given Sept. 15 at 8 p.m. in the Church of the Annunciation, 3810 Massachusetts Ave. NW. The concert, jointly sponsored by the church and the Assembly of Turkish American Associations, will include songs by Brahms, arias by Mozart, Verdi and Puccini, chamber music by Debussy and Ravel and a string quartet by Osman Kivrak, a Turkish American violist resident in Washington who will also perform. Other performers will include soprano Debra Lawrence, mezzo-soprano Patricia Miller, violinist Jody Gatwood, pianists Brian Ganz and Francis Conlon, and the Sunrise String Quartet. Information: 301-320-6952.

The Belgian pianists Steven and Stija Kolacny, well known in Europe as the Pianoduo Kolacny, will make their American debut this month with concerts of music for piano-four hands in Norfolk and Washington. Their first American tour, following successful engagements in Belgium, Austria, Germany, Italy, Slovakia, Latvia and Japan, is sponsored by the Flemish Community of Belgium. They have recorded five compact discs, including music of Schubert, Brahms, Dvorak and, most recently, the complete works for piano-four hands of Erik Satie. All these composers and others will be included in their free concert at 6:30 p.m. Sept. 16 in the Inter-American Development Bank.

The Opera Theatre of Northern Virginia will be trying a new approach in its production of "The Barber of Seville," scheduled for three performances on Sept. 15, 17 and 19 at the Thomas Jefferson Community Center in Arlington. Not only will it be sung in English, as this company's productions usually are, but it will be performed in a streamlined version, modeled on the Peter Brook adaptation of "Carmen" into "La Tragedie de Carmen," which scored an international success in the 1980s: The arias and ensembles will be linked by a narrator telling the story, rather than the sung recitatives heard in most productions; the singers will be in modern dress and two pianos will be take the place of the orchestra.

Winners: A free concert will be given Sept. 18 in St. Columba's Church on Albemarle Street NW by the Concord Ensemble, the newest group in the international early-music spotlight. Winners of the first Dorian-Early Music America competition in a field of more than 80 contestants, the ensemble is a six-voice a cappella male group based in Bloomington, Ind. Its first CD, "The Victory of Santiago: Voices of Renaissance Spain" (Dorian 90274), has just been issued. The disc, produced by Tina Chancey of Washington's Hesperus Ensemble, is the group's prize for winning the competition. It includes music of Tomas Luis de Victoria, Cristobal de Morales and other Spanish Renaissance composers who will also be featured in the concert. More information about the group is available at its Web site, www.concordensemble.com

The second Dorian-EMA competition has just been announced. It is open to EMA members living in the United States and Canada who have not issued a commercial recording; many fine groups in the Washington-Baltimore area should be eligible. Groups wishing to compete should send a letter of intent, specifying the repertoire to be submitted, by Oct. 15 to Early Music America, 11421 1/2 Bellflower Rd., Cleveland, Ohio 44106-3990. An audition tape will be due by Feb. 1.

Auditions: The Montpelier Cultural Arts Center in Laurel is accepting applications from classical 0musicians, college age or older, for its Spring Recital Competition. A 10-minute performance cassette should accompany applications, which are due by Oct. 15. For more information call 301-953-1993.