It sounds from our TV speakers as cameras pan across scenes of unimaginable destruction. It fills gaps between radio news reports of lives lost in the thousands and economic pain to come.

We retreat from stress by playing it on our stereos and pianos. We sing it in our churches and synagogues and mosques.

We have no companion dearer, in these difficult days after the terrorist attacks on New York and Washington, than music. Barber's "Adagio for Strings" calms our nerves.

Copland's "Fanfare for the Common Man" stirs our nobility and resolve. The Beatles' "All You Need is Love" and U2's "Peace on Earth" hold out hope for a better world.

Music is hardly the "universal language" of cliche. What speaks to one person may confound or even annoy another. But in very personal ways, we respond to it on deep emotional levels, in places words can't seem to go.

"For so many people, music is a source of comfort," says Dallas Symphony Orchestra music director Andrew Litton. "It's amazing how putting on your favorite song, or whatever, can so often make you feel instantly better or take you out of whatever mood you're in."

It matters not whether the music is high art or a barroom ditty. The tune of "The Star-Spangled Banner" was originally a drinking song. "God Bless America" began life in Irving Berlin's Ziegfield-style revue, "Yap, Yip, Yaphank."

The poetry of "The Star-Spangled Banner" is pretty purple, as is that of "The Battle Hymn of the Republic." The former's tune, covering an octave and a half, is notoriously unsingable; the latter's is almost a self-parody of dotted and drumbeat rhythms. "Extraordinary," Noel Coward wrote, "how potent cheap music is."

Patriotic songs have put plenty of lumps in our throats and tears in our eyes the past two weeks. With visions of passenger jets slamming into the World Trade Center burned into our retinas, Francis Scott Key's "bombs bursting in air" have taken on tragic new immediacy. No one alive today will ever again sing "America the Beautiful" without wincing at the line "Thine alabaster cities gleam, undimmed by human tears."

Unprecedented in human history, the terrorist attacks have left us feeling defiled and vulnerable. Fearful and angry and frustrated, we face a shadowy enemy. Words, whether threatening or consoling, fail us.

In times like these, even those who recognize no deity find in music--to co-opt a line from the Psalmist--"a very present help in trouble."

The Dallas Symphony Orchestra last weekend was one of doubtless dozens playing Barber's "Adagio for Strings." Broadcast on national radio at the deaths of Presidents Franklin D. Roosevelt and John F. Kennedy, this solemn essay in floating melody, building to an impassioned climax, then relaxing as in benediction, has become our de facto national threnody.

The ethereal Adagietto from Mahler's Fifth Symphony has also surfaced here and there. So has Elgar's noble Nimrod, from the Enigma Variations. The New York Philharmonic on Thursday replaced its originally scheduled season-opening program with Brahms' German Requiem, the composer's warm-hearted memorial to his mother.

Like most of us, Darren Keith Woods, the new general director of Fort Worth Opera, spent much of Sept. 11 watching TV. He worried about friends in New York.

"Finally, I had to turn off the TV," he says, "and I put on the Barber Adagio for Strings, and I just cried my eyes out. It was so cathartic.

"Music always imbues me with hope. I have to have it at the end of the day, when my brain is just crazy. That was just the perfect piece for me."

Laurie Shulman, program annotator for the Dallas and Fort Worth symphonies and other concert series, says she relieves anger and frustration by running a few miles. "But when I'm dealing with grief or sadness, I take much more comfort sitting down at the piano and playing Brahms."

Clearly, music can communicate emotion from one person to another. But by the usual standards of transmission, melody, harmony and rhythm are wildly imperfect. For all the analytical studies of Heinrich Schenker and other theorists, we're hard-pressed to agree on the denotation, let alone connotation, of so much as a single phrase.

Music is no more a "universal language" than Urdu. Hip-hop and Hindu ragas are as incomprehensible to me as a Gabriel Faure piano quintet is likely to be to a Zulu tribesman. We can learn new musical languages, just as we can learn new verbal tongues, but we rarely venture far beyond formative experiences.

And, as with speech, musical languages have dialects that challenge comprehension. There are people who thrill to Renaissance choral music who wouldn't be caught dead at a performance of La boheme, Beethoven lovers who can't abide Brahms.

Still, even music outside our routines can grab us and move us. With churches lately filled with people who usually sleep in on Sunday mornings, we've been reminded of the enormous power--alas, now rarely experienced--of communal singing.

The words have been as different as a mighty fortress and amazing grace and we shall overcome. The tunes have ranged from stern Lutheran chorales to rural folk tunes to African-American spirituals. In whatever guise, congregational singing can bind us together across regional, racial and religious divides.

"For most people, community singing provides more solace than merely listening to someone else sing," says Kenneth Hart, director of the sacred-music program at Southern Methodist University's Perkins School of Theology.

Hart also points out that TV often focused on hymn-singing in coverage of religious services in the days after the terrorist attacks.

"These people like (network news anchors) Ted Koppel and Peter Jennings, people who are seasoned and in some sense hardened by enormous experience, people who have seen it all, when they talked about the services, the first thing they mentioned was the hymns. They were amazed not from the esthetic point of view, but from the emotional."

Clearly, music touches us on a level quite different from language. Maybe it's a more primitive level, because babies "sing"--produce rising and falling inflections of tone--before they speak.

Scientific studies have demonstrated physiological effects of tone and rhythm--on heartbeats and respiration, brain waves and hormonal activity. Western music, at any rate, tends to be based on tension and release; Freud was not alone in relating it to sex. Some anthropologists have posited a physical need for music.

What's undeniable is that music opens a portal between our inner and outer selves. It can be a means of expressing, however vaguely, our own feelings, and it can give access to our emotions.

A piece of music can acquire associations very different from what its composer intended. Used in Luchino Visconti's film of Death in Venice and by Leonard Bernstein as a memorial to the slain Robert F. Kennedy, the Mahler Adagietto has acquired funereal associations. But recent scholarship has revealed that it was composed as a love letter to Mahler's young wife, Alma. Barber's Adagio, originally the slow movement of his String Quartet, was inspired by nothing more traumatic than a poetic image of a stream growing into a great river.

Music's ambiguity may be its greatest strength. "The real power of music," wrote philosopher Suzanne Langer, "lies in the fact that it can be true to the life of feeling in a way that language cannot; for its significant forms have that ambivalence of content which words cannot have."

In her book Feeling and Form, Langer proposed that, at its basis, music is "virtual time." It is a parallel universe in which we can both lose and find ourselves. And in time of trouble, it can be--as the Psalmist wrote of his Hebrew god--a "shield and buckler."

Noting television's startling juxtaposition last week of scenes of terrorist devastation with the consoling cadences of a performance of the Brahms German Requiem, New York Times music critic Bernard Holland wrote, "Art is our small, fragile claim to control over our lives. Terrorism offered us only uncertainty. Brahms brought the chill of uncertainty soothed by the knowledge of an outcome."

And he concluded, "Music is a form of protective gear against sudden violent death. It is thin and penetrable, but it may be all we have."