This week's major events are all of the vocal variety, some accompanied by orchestra on a vast scale and others in more intimate settings. More options, including a bevy of free concerts, can be found after the jump.

>> At the top of our list are the first National Symphony Orchestra concerts (October 16 to 18) conducted by the gifted Iván Fischer, featuring the third symphony of Gustav Mahler (pictured) in the Kennedy Center Concert Hall. German mezzo-soprano Birgit Remmert, who gave a promising performance in the work for David Zinman's Mahler cycle, will be the soloist. Singers from the University of Maryland Concert Choir and the Children’s Chorus of Washington will also perform in this grand "summer's dream," a work that Mahler once described as "an enormous laugh at the whole world." Tickets: $20 to $80.

>> Just as Mahler's third symphony epitomizes its era, the turn of the 20th century, Leonard Bernstein's Mass, an outrageous "theater piece for singers, players, and dancer," incarnates its time, 1971, when it was commissioned for the opening of the Kennedy Center right here in Washington. The hippies have taken over the Catholic Church, and while the result is nowhere near as profound as Mahler's third, the work is performed rarely enough that this week's performances from the Baltimore Symphony Orchestra (October 16 to 18) are a must-hear event. If the trip up to Baltimore is out of the question, the BSO will bring the work back to the Kennedy Center on October 26 at 4 p.m.

>> One of the best choral ensembles in the world, Collegium Vocale Gent from Belgium, will perform a delectable program of music by Haydn, led by fortepianist Kristian Bezuidenhout, on Friday (October 17, 8 p.m.) in a free concert at the Library of Congress. If you cannot reserve a ticket through Ticketmaster, show up early to wait on line for an unclaimed seat.

>> Any opera fan worth his salt will be making the trip to Baltimore's Shriver Hall on Sunday (October 19, 5:30 p.m.) to hear the recital by Ewa Podleś and pianist Garrick Ohlsson. The unclassifiable Polish contralto, who recently returned triumphantly to the stage of the Metropolitan Opera in La Gioconda, will sing songs by Chopin, Tchaikovsky, and Mussorgsky. Ohlsson will also perform some solo piano works by Scriabin. Tickets: $33 (students, $17).

MAKE IT FREE:
>> Help raise money for the Randy Hostetler Living Room Music Project by attending the free Benefit Concert tomorrow night (October 13, 4:30 p.m.). The program of music by living composers including D. Bermel, G. Sandow, R. Hostetler, M. Saylor, R. Woolf, and A. Gardner will be presented at the Sidwell Friends Upper School Performing Arts Center (3825 Wisconsin Ave. NW).

>> On Tuesday at lunchtime (October 14, 12:10 p.m.) cellist Vasily Popov and pianist Ralitza Patcheva will perform the free concert at Church of the Epiphany (1317 G St. NW).

>> Get your lunchtime music fix on Wednesday (October 15, 12:10 p.m.) with the free concert by pianist Michele Campanella, playing music by Domenico Scarlatti, in the East Building Auditorium of the National Gallery of Art.

>> The IBIS Chamber Music Society will perform music from film scores in a concert called IBIS at the Movies, at the Lyon Park Community Center in Arlington on Friday (October 17, 7:30 p.m.) and the Church of Clarendon on Sunday (October 19, 4 p.m.). Both concerts are free.

>> Bass Morris Robinson will give a free recital on Sunday (October 19, 3 p.m.) at the National Academy of Sciences (2101 Constitution Ave. NW).

>> Also on Sunday (October 19, 4 p.m.) pianist Mirjana Rajić will play a free concert in the elegant Music Room of the Phillips Collection. As always, you still have to pay to enter the museum.

>> The Festival Strings Lucerne will perform music by Brahms, Mendelssohn, and Sarasate during the free concert on Sunday (October 19, 6:30 p.m.) at the National Gallery of Art.

FURTHERMORE:
>> Winners of the Rostropovich Foundation Commemorative Scholarship will perform together on Wednesday (October 15, 7:30 p.m.) in a Tribute to Mstislav Rostropovich in the Kennedy Center Terrace Theater. Tickets: $35 to $60. For a free way to remember the NSO's late music director, you could also see the screening of the 1991 documentary film Soldiers of Music: Rostropovich Returns to Russia on Thursday (October 16, 7 p.m.) at the Library of Congress.

>> On Thursday (October 16, 7:30 p.m.) Edwin Good will play a recital of historical and contemporary music on a reproduction of a 1722 Cristofori piano, in the Mansion at Strathmore. Tickets: $25.

>> The lovely and also talented Eroica Trio will perform music by Lalo, Martinů, and Schubert in a concert on Friday night (October 17, 8 p.m.) in the Barns at Wolf Trap. Tickets: $35.

>> Virginia Opera brings its production of Verdi's Il Trovatore to the George Mason University Center for Fine Arts (October 17 and 19). Tickets: $44 to $86.

>> Members of the Washington National Opera's Domingo-Cafritz Young Artists program will perform a concert called The Unknown Bizet on Saturday (October 18, 7 p.m.) at La Maison Française (4101 Reservoir Rd. NW). Tickets: $25.

>> For more concert information, go to Ionarts.