Maestra.(Baltimore Symphony Orchestra's Marin Alsop)

"DON'T LET HISTORY PASS YOU BY!" proclaims a banner hanging outside Joseph Meyerhoff Symphony Hall, in Baltimore. The history in question belongs to Marin Alsop, who took over as the music director of the Baltimore Symphony last September, thereby becoming the first woman ever to lead a major American orchestra. Or so some say. A recent front-page story in the Buffalo News declared that the Buffalo Philharmonic--a seasoned, skilled, and not exactly minor group--made this history back in 1998, when it hired the conductor JoAnn Falletta. The League of American Orchestras, asked to adjudicate the dispute, noted that orchestra insiders use the word "major" to indicate an ensemble that plays year round: Baltimore does, Buffalo does not. Whatever the outcome of that controversy, female conductors remain embarrassingly rare. The problem isn't that misogyny runs rampant in the music world; it's that the classical business is temperamentally resistant to novelty, whether in the form of female conductors, American conductors, younger conductors, new music, post-1900 concert dress, or concert-hall color schemes that aren't corporate beige.

The Baltimore Symphony, along with several other orchestras based in troubled American downtowns, has struggled in recent years, its finances periodically in crisis and attendance falling perilously low. The previous music director, Yuri Temirkanov, was a maestro in the traditional mold, a fervent interpreter of familiar repertory. Alsop, a fifty-one-year-old New York native, is quite different, and not just because of her gender. She is a forceful advocate for new music, and has said that she wishes she had been a composer--that conducting is for her a vicarious way of entering into the creative process. All non-composing conductors probably feel the same, but most find it convenient to confine their attentions to the safely deceased. Dead composers don't speak up and ask for more felt on the bass drum; they don't annoy orchestra players reluctant to learn a brand-new score that they might never play again; and they generally don't send listeners running for the exits. Alsop, in previous appointments at the Colorado Symphony and at the Bournemouth Symphony, has shown a knack for charming both players and audiences into enjoying music that they think they won't like. She has become a star, in part, by making composers the stars. She is on her way to accomplishing the same feat in Baltimore--or so it seemed at two concerts this fall.

Alsop's inaugural season is startlingly ambitious. Eleven living composers--John Adams, Tan Dun, HK Gruber, Aaron Jay Kernis, Mark O'Connor, Steven Mackey, Christopher Rouse, James MacMillan, John Corigliano, Thomas Ades, and Joan Tower--make appearances, and they are represented by more than the seven- or eight-minute aural hors d'oeuvre that too often passes for new-music programming. Five of them occupy the entire first half of a program, with a Beethoven symphony after intermission. Composers in Conversation events allow the visitors to explain their visions. To encourage newcomers, the orchestra slashed prices on regular subscription series to twenty-five dollars a night, making up the financial difference with a million-dollar grant. Students are offered a package of five concerts for twenty-five dollars. Whatever excuses Baltimoreans may supply for skipping classical concerts, high ticket prices can't be one of them.

Now halfway through the first season, the orchestra has reported an upward bump in attendance. A healthy crowd showed up for a concert that paired two works by Kernis--"Newly Drawn Sky" and "Lament and Prayer"--with Beethoven's "Pastorale" Symphony. John Adams drew a sizable house for his concerts; Tan Dun's sold poorly. Alsop recognizes that, for the moment, she is more of an audience draw than the composers for whom she has such obvious affection. She's facing a familiar dilemma: on the one hand, she must convince traditional concertgoers of the value of Adams and Ades; on the other, she must convince younger listeners of the relevance of Beethoven. "I don't think I'm being naive, but I try not to even think about it," she told me, when I stopped by her dressing room after her public conversation with Kernis. "I simply try to treat all music the same."

A protegee of Leonard Bernstein, Alsop takes an intensely physical approach to conducting, leading as much with her upper body as with her forearms and hands. Spontaneous in spirit, she often changes tempi and details of phrasing from performance to performance. Musicians can find that kind of unpredictability frustrating; during one rehearsal, a player tried to get her to commit to a consistent pacing of a ritardando in the "Pastorale," whereupon she jokingly said, "I have an issue with commitment." (When Alsop's appointment was announced, in 2005, much of the orchestra rose up in protest, telling the press that she was glib and imprecise. This rebellion, it turned out, had more to do with player-management tensions than with Alsop herself. A new C.E.O., Paul Meecham, has established a more convivial atmosphere.) The ...