After lying dormant for most of the summer, the Classical Music Agenda stirs to life in the first week of September, as news of upcoming concerts filters into the mailbox. Washington offers an extraordinary number of free concerts most weeks, so we will start there.

THE FREE KIND:
>> You read earlier this week about the free simulcast of the opening night of Washington National Opera's production of La Traviata at Nationals Park (September 13, 7 p.m.). You can supposedly register for "VIP seating" through Wednesday, and we have since learned that the concessions stands will be open for business. If you want a real seat, in the Kennedy Center Opera House, good luck finding a ticket, but the run continues through October 5 and some tickets remain.

>> Fill up the rest of your Saturday (September 13) with a visit to the Open House Arts Festival at the Kennedy Center, between 12 noon and 11 p.m. It's free, there are lots of performances of all different kinds, but my visits in recent years have been less and less enjoyable because of the crushing crowds.

>> On Monday (September 8, 8 p.m.) trombonist Christopher Dudley, a faculty member at the University of Maryland, will give a free recital at the Clarice Smith Center.

>> The Church of the Epiphany continues its lunchtime concert series downtown with a recital by pianist Jeffrey Chappell on Tuesday (September 9, 12:10 p.m.). These programs usually last an hour or slightly less, and a donation for the performers is accepted.

>> The young pianist Sara Daneshpour, a student of Leon Fleisher's, will give a free recital on Sunday afternoon (September 14, 3 p.m.) in the auditorium of the Reynolds Center for American Art and Portraiture. Free tickets will be distributed, starting one hour before the concert, in the building's G St. lobby.

FURTHERMORE:
>> On Saturday evening (September 13, 6 p.m.) the Emerson Quartet begins its season of concerts on the Smithsonian Resident Associates program, at the National Museum of Natural History. The program includes string quartets by Haydn (op. 74/2), Dvořák (E-flat major, op. 51), and Ravel (F major).

>> The ground-breaking cellist Matt Haimovitz has made a career out of playing in unorthodox settings, like bars and clubs. He will perform a recital, with pianist Geoff Burleson, on Sundy evening (September 14, 7:30 p.m.) at the Jewish Community Center of Greater Washington in Rockville.

>> The National Symphony Orchestra eases into the fall schedule this week with two programs of Hollywood film music, on Thursday (September 11, 8 p.m.) and Friday (September 12, 8 p.m.). Richard Kaufman stands in as guest conductor at the Kennedy Center Concert Hall.

>> On Saturday (September 13, 8:30 p.m.) the Baltimore Symphony Orchestra opens its season with a Gala Celebration Concert, featuring cellist Yo-Yo Ma, at Meyerhoff Symphony Hall in Baltimore. Music Director Marin Alsop will conduct, and tickets are priced at a Gala Celebration rate.

>> Pianist Frank Conlon will perform with Viva La Voce on Sunday (September 14, 4 p.m.), on the Amadeus Concerts series at St. Francis Episcopal Church, in Great Falls.

>> For more concert information, go to Ionarts.