Anyone who has attended one of the American Composers Orchestra's sold-out Orchestra Underground concerts at Zankel Hall has undoubtedly felt the excitement of being part of a new scene. Unlikely repertoire combinations are juxtaposed, multimedia components are frequently incorporated into the musical proceedings, and musicians sometimes are positioned in the hall beyond the proscenium, a sonic feat for which the malleable Zankel is ideally suited.

"The remarkable catalog of American music played by the American Composers Orchestra at Carnegie Hall has come to be expected," says Carnegie Hall's Senior Director and Artistic Advisor, Ara Guzelimian. "But, with the advent of its new Orchestra Underground concerts at Zankel Hall, it has also added a wonderfully provocative edge to its programming."

Provocation has even carried over into the orchestra's one concert this season at Carnegie Hall's Stern Auditorium on Wednesday, February 23, at 8 p.m., which consists entirely of world premieres. Schizophrenic's Serenade by new-wave rocker turned film composer Danny Elfman shares the bill with Dark Florescence, a unique double guitar concerto (for the unlikely combination of acoustic and electric guitars) by post-minimalist pioneer Ingram Marshall. The boundary-defying soloists are virtuoso Benjamin Verdery, who has recorded songs by Prince in arrangements for classical guitar, and Andy Summers, formerly of the Police. Also featured is the symphony Blanco, Azul, Rojo by Manly Romero, who was chosen for this commission in 2003 out of eight finalists in the Whitaker Readings for Emerging Composers‹an annual program of the American Composers Orchestra that shines light on exciting new voices.

From its very beginning, the American Composers Orchestra set itself apart from other orchestras through its commitment to music created in this country. As composer Francis Thorne (one of the ACO co-founders) remembers, in the days before the ACO "only six percent of the music played by the major orchestras in this country was by American composers, and, if you removed Bernstein, Copland, and Barber, it was only 1.7 percent!" The seeds of what the ACO would eventually accomplish were already being planted with its very first concert in Alice Tully Hall on February 7, 1977. Bringing together works by composers as diverse as Lou Harrison and Yehudi Wyner, reviving a neglected classic‹Wallingford Riegger's Third Symphony‹and commissioning a brand-new composition for orchestra with electronics by Charles Dodge, who was then in his early 30s, that concert laid down the blueprint for many of the ACO's most enduring legacies over the next quarter century.

Just as our world has been transformed in ways we never would have imagined back during the first hundred days of Jimmy Carter's presidency, our cultural landscape has also changed greatly in ways that have been both exciting and challenging. Self-publishing composers, the indie-cred of boutique record labels, orchestras competing for composers-in-residence, music videos, personal computers, and the Internet were, for many of us, not even dreams back then. But the ACO kept dreaming throughout all these cultural transformations, creating a legacy that now extends to performances of music by nearly 500 American composers, including more than 100 world premieres and newly commissioned works, with an average of four new works per season. The participating composers have ranged from minimalist pioneers Philip Glass, Terry Riley, and John Adams to Milton Babbitt and Charles Wuorinen, the leading torchbearers for advanced serialism; from maverick experimentalists such as John Cage, Robert Ashley, Laurie Anderson, Henry Brant, George Lewis, and the founders of Bang on a Can to the very first orchestral commissions by some of today's most important voices in orchestral music, including Joan Tower, Ellen Taaffe Zwilich, and Joseph Schwantner.

The ACO began its residence at Carnegie Hall during its tenth anniversary season in 1985-86. At the same time that it was bringing so much exciting new music to the stage of Stern Auditorium, the orchestra was also planning other ambitious projects. Some of the most talked about events in New York have been ACO-hosted festivals, including concerts and discussions in a variety of venues in addition to culminating orchestra concerts at Carnegie Hall.

From 1994 to 1999, under the artistic leadership of composer Tania León, the ACO challenged us to rethink our definition of "American" by embarking on an unprecedented six-year journey exploring music from composers beyond U.S. territorial borders. Each year, the weeklong Sonidos de las Américas shone light on the music of a single Latin American country and provided an exciting cultural exchange between a visiting delegation of composers and a group of composers from the United States. Would that world politics could operate as fluidly! In 2001 ACO similarly redefined the word "orchestra" by convening the first-ever National Conference on Technology and the Orchestra, Orchestra Tech, under the guidance of composer Tod Machover. According to Machover, "Orchestra Tech helped establish an ongoing forum to help put orchestras back in a leadership position regarding new tools and how they might best be used to enhance what happens onstage and to break down boundaries between performers and audience." Just last season, Improvise! devoted an entire week to an exploration of the possibilities of integrating improvisation and the orchestra. Alvin Singleton, who, along with Anthony Davis, served as the series' composers-in-residence and artistic advisors, says: "Improvisation today is one of the more important ways of creating music, not only in jazz but in concert music as well. Today's orchestral musician has more to say technically than anyone could ever put on a page."

But Orchestra Underground might ultimately prove to be the ACO's most challenging project yet. Zankel Hall has liberated the orchestra to think unconventionally and Michael Geller, the ACO's Executive Director, promises that the best is yet to come. "Looking to the future, ACO will be a catalyst," he says. "We certainly don't know all the answers about the future of American orchestra music, but there are a lot of great questions out there that will continue to motivate us and inspire new and provocative musical programs."

Frank J. Oteri is a New York-based composer and the editor of the American Music Center's Web magazine, NewMusicBox.org.