A soundscape beckons a listener to enter, to reflect, and to remember

The theaters and the concert halls of New York City went dark after the attacks on Sept. 11, 2001, but it was not long before arts institutions began grappling with how to respond. Less than six months later, the New York Philharmonic announced it would commission a new 9/11 memorial work from the American composer John Adams to open its 2002 season.

It would be a hugely daunting assignment for any artist: Was it not too soon to contemplate a meaningful memorial? What would a proper musical response to 9/11 sound like? And how might a Bay Area composer speak for New York and an entire wounded nation, let alone for the families of the victims?

Adams rose magnificently to the occasion, and the work he composed -- ``On the Transmigration of Souls " -- proved he was an inspired choice. The composer's master stroke was to cast his piece not as an orchestral dirge or somber tone poem, not as an artist's subjective response to the tragedy, but as a kind of anti-oratorio, or, as he put it, a ``memory space" that beckons a listener to enter it like a room, to reflect and to remember.

Written for orchestra, adult chorus, and children's chorus, the piece opens with wisps of everyday street noise instantly evoking New York City: a truck rumbling by, the sound of footsteps on pavement. This gives way to a series of haunting fugues built out of the found materials of mourning: a boy intoning the word ``missing," the names of victims recited in quiet clarity, descriptions lifted from the heartbreaking posters that once lined the streets (``Eye color: hazel; Hair color: brown"), personal testimonies (``He used to call me every day. I'm just waiting"), and even stunned observations from a flight attendant aboard one of the planes (``I see water and buildings . . ."). Framed by ethereal choral lines and supported by an empathetic orchestra, the individual names and memories crisscross and blur into a hazy collage, one part Charles Ives , one part Maya Lin , many parts John Adams.

To be sure, the use of such raw material plucked from the rubble of that tragic day might have felt manipulative in less skillful hands. But Adams shows tasteful restraint and a respectful ear. The textures are crystalline; he avoids bathos but does not shy away from real emotion. At one point the brasses thunder over a fevered chorus and a sea of surging strings. But the dissonant chaos soon recedes, and the engrossing tapestry of memories returns.

Commemorative works tend to have a short shelf life, as they are so overtly tied to the ephemeral world of current events. But five years later, 9/11 is still very much with us, and Adams's piece has received wide exposure and many accolades, including the Pulitzer Prize . It was recorded (on Nonesuch ) and is being performed this season by major orchestras in the United States, Canada, and Germany.

The broad appeal of ``On the Transmigration of Souls" ultimately comes from its artful artlessness: that is, the way Adams applies his highly original vision and technique to embrace the language of ordinary men and women mourning their loss in the simplest of terms. It is a heartening example of contemporary classical music escaping from its ivory tower to address a momentous national event in a distinctive yet accessible way.

The work's sincerity feels all the more precious now that the tragic events have become fodder for politicians and plans for an actual memorial structure at ground zero have progressed so slowly. Who knows what the site will look like in another five years, but in the meantime we have Adams's soundscape of vast proportions and its uncanny power to evoke the memories of an unforgettable day.

Jeremy Eichler begins as the Globe's classical music critic on Sept. 18.