Independence Day is coming. It's early evening in Kingston, the capital of Jamaica, and the slumbering hills that surround the city are covered in warm blankets of shadows. It has been a season of heat—the sugarcane crop is shriveling for lack of rain, the streets are dusty and dry, and tensions are simmering. Last month there were riots as citizens clashed with police. Last night, at a Montego Bay concert, there was gunfire, a stampede, injuries.

But Independence Day is coming, the 39th anniversary of Jamaica's emergence from the control of Britain. Outside club Asylum, one of the city's most popular night spots, young Jamaicans—in their teens, 20s and 30s—have begun to gather. Inside, things are slow as the drone of foreign acts—Britney Spears, Whitney Houston, 'N Sync—echoes across the empty dance floor. But out on the streets, kids are making their own scene, to their own sounds. It is a scene like those that nowadays are taking place in cities all over the planet—in Tokyo, in Cape Town, in Reykjavik. In such ways, in such places, a fresh sound in global music is being born. It's the beating heart of a new world.

On the street outside club Asylum, ragga (a rap-influenced form of reggae) booms out of parked cars. Young Jamaican men with white scarves tied around their heads vibrate to the music, thrusting their hips at passing Suzuki Samurais. The youths have now begun to slow up traffic, and police close in on them like parentheses. Is a confrontation brewing? One young reveler reaches into his car and turns up his stereo. The voice of Elephant Man, the latest local ragga star, blares out, heavy with attitude and thick with patois: "Badman nah run from police inna shootout/Whole crew a government see dem pon di lookout..." The youth smiles at the cops and keeps dancing.

Bob Marley, the great Jamaican Reggae star, once posed the question "Won't you help me sing these songs of freedom?" Music can be a tool: for relaxation, for stimulation, for communication—and for revolution. In fact, it is often a rhythm of resistance: against parents, against police, against power. The U.S., in this one-superpower age, has perhaps never been so dominant—economically, militarily, culturally. That strength attracts immigrants, who bring with them new forms of music. And that strength also inspires competition, as musicians and performers in other countries, mindful of the American hegemony, assert their national identities and culture and create new musical genres they can call their own: garage in Britain, kwaito in South Africa, ever evolving forms of reggae in Jamaica. America may be the world's policeman, but citizens of the world—and the New Americans who have come here—have turned up their car stereos and are dancing like never before.

The quest for change has often been a family affair: many top global-music performers, including Nigeria's Femi Kuti (son of Fela), Jamaica's Ziggy Marley (son of Bob) and Brazil's Max de Castro (son of Wilson Simonal), are the children of musical pioneers. Now, around the world, old traditions are being revived, remolded and returned to prominence by a new generation and new technology. In Tijuana, Mexico, young DJs are crossing traditional norteno (a polka-like music) with not-at-all-traditional techno to create a fresh genre, Nortec. In Bogota, Colombia, the rock duo Aterciopelados is mixing old-time accordion-driven vallenato with clubland drum-'n'-bass beats. In Rio de Janeiro, Brazil, the great chanteuse Marisa Monte is smoothly blending samba and art-pop.

Centuries of customs have changed in just decades. In the 1940s and '50s, radio brought the music of the outside world to much of Africa for the first time. In the 1970s, audiocassettes made it possible for Third World musicians to disseminate their own music quickly, cheaply and profitably. Acts like the Congo's Papa Wemba became continent-wide superstars.

In the 21st century, the Internet has opened up the world to itself. In the distant past—say, three years ago—global-music fans had to wait for a record label to decide whether to distribute a foreign artist in their country. South African diva Brenda Fassie's last three CDs weren't picked up by American distributors, despite the fact that they were best sellers in Africa. Today, Internet file-sharing services allow users to listen to whatever they want, anywhere they choose, anytime they please. (And Fassie's Stateside appeal is recognized by some: Banana Republic plays her song Vuli Ndlela in its stores.) Conflicted about the ethics of unauthorized file sharing? Online music stores—which tend to have wider and more eclectic inventories than their bricks-and-mortar counterparts—allow fans to buy hard-to-find CDs (like, say, the excellent compilation Zimbabwe Frontline 3: Roots Rock Guitar Party) quickly and conveniently, albeit sometimes expensively.

The we-are-the-world maxim is this: music is the universal language. For the mainstream record industry in the U.S., however, music in languages other than English often wasn't considered universal; it was controversial.

Richie Valens hit it big with La Bamba in 1959. The music industry didn't wholeheartedly embrace another Latin rocker until Santana's autumnal success in 1999.

Now tongues are coming untied. Wyclef Jean's platinum hip-hop CDs, The Carnival and The Ecleftic, mixed English and Haitian Creole. Christina Aguilera, who launched her career singing English-language teen pop, recorded a CD entirely in Spanish last year. Increasingly, world-beaters are collaborating and connecting with one another. Colombian rocker Shakira's new CD was executive- produced by Cuban-American Emilio Estefan Jr. and draws from Argentine tango.

The new global music doesn't exclude America. After all, America's biggest rock star, Dave Matthews, is a white African; Japan's biggest pop star, Utada Hikaru, hails from Manhattan. The old-school term world music is a joke, a wedge, a way of separating English-language performers from the rest of the planet. But there has always been crossover. In 1958 Dean Martin scored a hit with the Italian tune Volare; in 1967 Frank Sinatra recorded an album of songs by Brazilian composer Antonio Carlos (Tom) Jobim. Elvis Presley's Can't Help Falling in Love is based on the 18th century French ballad Plaisir d'amour. Such music became world music only when darker-skinned folks sang it.

Pop music and global music aren't mutually exclusive categories. In the '80s Paul Simon, David Byrne and Peter Gabriel blended world beats. More recently, Sting scored a hit with Algerian rai star Cheb Mami, Lauryn Hill covered Bob Marley on MTV Unplugged, and Britney Spears has made a habit of working with Swedish songwriter Max Martin. Madonna, on her latest tour, drew from so many cultures for sonic and sartorial inspiration, it was a surprise Kofi Annan didn't join her for an encore.

Musicians performing in different languages often strike similar chords. Listen to the intense, undulant wail of Assane Ndiaye on the song Nguisstal, a track on Streets of Dakar: Generation Boul Fale, a compilation of young Senegalese acts. Boul fale is a Wolof phrase that means, loosely, "Never mind." The American punk group Nirvana's seminal album of teen angst was also titled Nevermind. Alienation, it seems, is a nation without borders.

Lyrics are important, but they don't have to matter. Even when Bob Dylan, arguably America's finest lyricist, mumbles through a number, the poetry of his words comes out in the phrasing. "How does it feel?" Dylan famously asked on Like a Rolling Stone. We may not have known exactly what he meant, but we knew how it felt. Today's musicians have taken that lesson to heart. Thom Yorke of the British band Radiohead wrote some songs for his album Kid A by cutting up lyric sheets and pulling lines out of a top hat. The Icelandic band Sigur Ros sings some songs in a made-up tongue it calls Hopelandic.

Many of today's global musicians move back and forth from their native tongues to English, on the same album, sometimes on the same song. There's a sense that geography doesn't have to equal destiny. The Tokyo-based rock trio the Brilliant Green's latest CD is almost entirely in Japanese. It was recorded in Tokyo. The CD's title? Los Angeles.

Listening to music in an unfamiliar tongue can be more thrilling than listening to a song whose lyrics are instantly intelligible. Because if you can connect with another person beyond lyrics, beyond language, then you have engaged in a kind of telepathy. You have managed to escape the mundane realm of ordinary communication and entered a place where souls communicate directly. It's cooler than instant messaging. Cherif Mbaw, 33, is a Senegalese singer-guitarist living in Paris; the songs on his brilliant CD Kham Kham are in his native Wolof. But when Mbaw, with his beatific tenor, soars into a passage of staccato vocals and jittery guitar work on Saay Saay, you know exactly what he means even if you don't know what he's saying. His intent is in his inflection; his eloquence is in his emotion. Boundaries fall away.

So, Independence Day is coming. It's late evening on Knutsford Boulevard in Kingston. The young Jamaicans who were outside club Asylum are safely inside. The riots, the tension—all forgotten, and perhaps they were overplayed by the press from the start. Jamaican tunes blast from the speakers; the dance floor is packed. One of the most popular ragga songs this season is Shake Yuh Bam Bam by the group T.O.K. The song samples Ricky Martin's hit Shake Your Bom-Bom but adds ragga's roughness. When Bam Bam comes on, the crowd goes wild.

Is a sense of cultural uniqueness lost in the global-pop blender? If they are grooving to Ricky in Kingston, is there anywhere to hide? The first moments of the 21st century have been haunted by the specter of globalization, of a star-spangled world in which a parade of powerful letters—the U.N., the WTO, the IMF—hammers the diversity of the planet into homogenized goop. But Aterciopelados insisted on recording its latest CD in its hometown of Bogota. And Max de Castro projects blown-up images of old Brazilian LPs at some of his concerts to remind audiences of his country's heritage. Many new global artists have the curiosity to wander the earth with their music and the integrity to stay connected to their homelands. This is the help Marley asked for. These are freedom songs.

It's getting hot in club Asylum, but the dancers just keep on going. Outside, the cops are putting up barricades for tomorrow's celebrations. Inside, the party has already begun. At this club and ones like it around the world—in Sao Paulo, in Dakar, in Havana, in New York City—Independence Day is every night.