Go-Go-Go Beat

But wait, there's more. Nascent and aggressive satellite radio companies advertise a whole new explosion of music possibilities. Sirius promises 65 channels of music; XM offers 67. Oakley's Thump sunglasses contain a tiny digital music player, and cell phones everywhere ring to the opening bars of "Stairway to Heaven."

Music is a luxurious necessity. "There has never been a human culture existing or extinct that has not had music," says Mark Tramo, a neuroscientist at Harvard Medical School who believes that music is a universal language.

Certain melodies inspire, arouse, invigorate. Others provoke, insult, infuriate. As we've learned from watching decades of movies and TV shows, effective music can move us to tears and to cheers. It pumps up the color and texture of reality; the mundane morphs into art. We subconsciously listen for resolution in music, the way we naturally yearn for color-wheel answers in paintings and solutions to well-written mysteries.

Music can be oh so social -- uniting us, family-like in a harmonious unbroken circle of fellowship. "We Are the World" comes to mind. Music can also be divisive, serving as a wedge between cultures or genders. The misogynist "Superman" by Eminem, for instance. Ever since the first Walkman appeared in 1979, social scientists have railed against the alienation caused by personal music devices. And other scientists have warned us of the inevitable deafness and cerebral distraction.

We consume music and music consumes us. We are caught in the middle of a musical war. Whole industries are built on dumping music upon us, while others allow us to choose the music we want to listen to. The armies can be divided into those that overpower and those that empower. It's a battle royal for our ears, our brains, our bank accounts. As a result, never before has there been so much music -- good, bad, harmonic, atonal -- available.

As composer Libby Larsen puts it, "Recording technology has made us all digital democrats." Music today is free-flowing, intoxicating, addictive, and it's no wonder that some people, like Cabrera, just can't get enough of it.

Music on the Brain

They are -- Cabrera and his ilk -- the musicholics: disengaged folks with small, sleek digital players in their hands or pockets who, to varying degrees, need music like they need oxygen. They carry CD players and MP3 gadgets. Many depend on Apple iPods: 10 million have been sold since the device was introduced in November 2001. And there are more and more portable satellite radios and music-playing cell phones showing up on store shelves every day to feed the musical habit.

They are people like:

· Demisha Camp, 21, in a T-shirt and bluejeans, strolling through the Fashion Centre at Pentagon City. She's on her way to a hair salon where she works as a shampooer. She's listening to Faith Evans on her CD player. "I have to work with music," she says. "I can't focus without music or sound."

· Marsha Guery, 20, on the Green Line headed toward Howard University, where she is a fashion merchandising major. She's communing with Amarie on her Sony MiniDisc player. She likes to have music on all the time. Her parents often say to her: Get that music out of your ears! You're not paying attention! But she likes the feel of the sound. "When I walk down the street," she says, "I'm in my own little world."

· A woman in silver slippers at a back table in the upper Georgetown Starbucks. She is studying for a science exam and listening to music on her compact disc player. She loves to listen to music while doing other things, she says. On the table, a paperback textbook lies open. There is a full-page diagram of the human brain.

So apropos. The music, the brain, Starbucks.