The fall season is a time of firsts: first days of school, opening nights, and, in Washington this fall, first hearings of plenty of new music. But “first” is an elusive term when it comes to performance.

When it comes to new music, classical music presenters face a conundrum. If you mount a premiere, you get media and audience attention; but if you give a second or third or fourth performance of a work, you get none of that cachet. Yet you can’t only play brand-new works. Music has to have repeated hearings if it’s to penetrate the ears and minds of listeners. Furthermore, commissioning is expensive. In the age of recession, co-commissions have emerged as an answer to both problems: a group of institutions get together and commission a new work, and each gets bragging rights to a local premiere.

The biggest “first” of this nature in Washington this fall is Love Fail (Nov. 28), a co-commission of the Fortas Chamber Music Concerts at the Kennedy Center with a host of other high-profile institutions. The piece is an evening-length theater piece by David Lang, whose Pulitzer Prize win in 2008, for “The Little Match Girl Passion,” managed to catapult him from maverick status to a member of the establishment. “Love Fail,” which combines medieval lays, the libretto of Wagner’s “Tristan und Isolde” and short stories by Lydia Davis in a single narrative of love gained and lost, was written for the vocal quartet Anonymous 4; Lang, who has also written for the Trio Mediaeval and the Theatre of Voices, has a particular penchant for a capella sound. The work had its premiere in June at the International Festival of Arts and Ideas in Connecticut, and goes on from here to other co-commissioners, including the Next Wave Festival at the Brooklyn Academy of Music.

Another “first” is offered by the enterprising Fairfax Symphony Orchestra, which deserves a lot more attention than it gets in Washington’s shadow. To start its third season under its music director, Christopher Zimmerman, on Sept. 22, it’s offering an American program that includes the local premiere of “Shadows” by Ellen Taaffe Zwilich, who won her own Pulitzer Prize in 1983 (the first female composer so honored). “Shadows” is a piano concerto written for Jeffrey Biegel, himself a former winner of the Kapell Competition, who helped organize a consortium of 10 orchestras to bring about the commission, raised some of the funds on Kickstarter, and gave it its world premiere with the Louisiana Philharmonic Orchestra in 2011.

Another kind of “first” is a piece that may have been done in the region before, but that a company or ensemble is taking on for the first time. Oct. 4-6, for example, sees the National Symphony Orchestra’s playing Peter Lieberson’s “Neruda Songs,” which the Boston Symphony Orchestra brought to Washington in 2006, but which will have its first NSO performances, conducted by Christoph Eschenbach (Kelly O’Connor is the soloist). These songs, written for Lieberson’s wife, Lorraine Hunt Lieberson, shortly before her death in 2006, are some of the greatest love songs written in the past 100 years, given added poignancy by the passing of both artists at relatively young ages; Lieberson himself died in 2011.

And the Virginia Opera has started a whole series of “firsts”: It plans to open every season from now on with an opera the company has never done before. This year it’s Bizet’s “The Pearl Fishers,” heard not long ago at the Washington National Opera but being performed for the first time in the Virginia Opera’s 37-year history (Oct. 12 and 14), and also marks the company debuts of the conductor Anne Manson and the stage director Tazewell Thompson. That this opera is enjoying its Virginia Opera premiere nearly 150 years after it was written shows that “firsts” are in the eye of the beholder.