In fact, much of what's being called "world music" is much truer to the sources or rock-and-roll inspiration than the latest crop of neo-punks. Wanna-B-Boys, third-generation hippies, and self-conscious punks, all vying to be the biggest clichés - it gets stale quick, but what's a hipster to do? In fact, there's every reason to believe that the real vitality of the music scene is being forged not on 120 Minutes but in ethnic pop like that of the late, deitized Selena: music from a Latino superstar who learned Spanish as a second language and sang with Madonna-like bravura married to Tex-Mex conjunto roots and disco production. You can open your ears and hear the latest exotic sounds in pop all over town, and you don't necessarily have to wait for the latest tour by Nusrat Fateh Ali Khan or the Master Musicians of Jajouka to do it.

Club 3 is in a section of Somerville that seems light years from Rio's beaches. The dusty plastic ferns hanging from the ceiling hardly evoke the Amazon basin. But on Sunday nights the place bounces to the beat of Brazil. Its proximity to Union Square, with that area's pan-Lusitanian splendor, means the club attracts music lovers from the Azores and mainland Portugal, as well as from the Hub's Brazilian community.

Brazilian music is not exactly alien to the American ear. From "The Girl from Ipanema" to Paul Simon's Rhythm of the Saints, it has made its mark. We all know about the samba, the bossa nova, the lambada. Yet the huge land continues to produce sounds vital and surprising enough to quicken the pulse of the most jaded gringo.

The New Amazonas, who often play Club 3, are a good case in point. Their repertoire consists mainly of covers from the Brazilian Top 40. Yet as drummer Alberto Netto explains, their arrangements tend to favor the distinctive Axe rhythms of the northeastern state of Bahia. Another ingredient is olodum, a percussive style that the famous Brazilian ensemble Olodum is named after, with roots in West African religion. Reggae also finds its way into the mix, as does a chugga-chug reminiscent of rockabilly. In this age of airborne immigration, such stylistic interdependence is quickly becoming the norm. Indeed, you might wonder whether a concept like "worldbeat" has any value. Does it open ears and minds, as its idealistic devotees believe? Or is it simply a marketing category, one that ghettoizes international artists whose reach is truly global and not restricted to any "indigenous" aesthetic?

Consider Irish music. The Brendan Behan Pub, in Jamaica Plain, is one of a half-dozen Irish-style bars around town that have real Irish music. Except for its presence in a largely Hispanic neighborhood, the Behan could be in Galway or Cork. Its entertainment roster includes many rock and folk acts that are not especially Hibernian. But on Tuesday nights the big draw is the seissiún, a freewheeling traditional jam.

Fueled by fiddles, the bodhrán, and the dulcimer, the lively sound of the seissiún is far removed from the maudlin ballads long cherished by Irish-Americans. Even before the great migrations of the 1840s, Scots-Irish settlers in the Appalachians introduced many of the motifs found in country music. When country met R&B, the byproduct was rock and roll. In the '60s, Van Morrison started singing the blues in Belfast, and the whole thing came full circle. Thus Thin Lizzy, the Undertones, and of course U2, an export to rival Guinness. Clannad and the Cranberries are equally valid expressions of the Irish experience.

The Brendan Behan is, to say the least, an intimate venue. By contrast, the Middle East Restaurant has grown into an indie-rock multiplex, a year-round Lollapalooza where you can score some baba ghannouj. Yet the place began and remains a working Middle Eastern restaurant. This heritage is exposed on Wednesday nights, when the bakery resounds with belly-dancing music.

"I don't consider myself a top player," says Nick Samra. This too modest assessment of his talents is based on his limited formal training on the oud, a fretless stringed instrument that inspired the medieval lute and the modern guitar. Schooled or not, his playing is masterful and dynamic.

Samra's parents, who came from Syria, fostered his love of music, but his family included no musicians. By contrast Leon Manoogian's grandfather was a Turkish-Armenian drummer. But when he himself picked up the sticks, it was rock that won his heart. Only at 22 did he take up the dumbek, a small drum whose sinuous rat-tat-tat links Samra's ethereal runs to the more physical charms of the dancers.

The two frequently sit in with guest musicians, some from as far away as Marrakesh, some from Inman Square. Sahar, though primarily a dancer, sometimes adds percussion. Her commitment to Arabic dance (she dismisses "belly dancing" as an American neologism) is total and impressive. A frequent headliner, she also designs costumes and gives lessons to less experienced dancers.

All three point out that music is not simply a matter of accompaniment, insisting that melody and motion are both integral parts of the performance. As Sahar puts it, "Something about those quarter tones just makes you want to move."

Between French colonial rule and our own tragic involvement, Vietnam has long been exposed to Western popular music. Ho Chi Minh City (the former Saigon) is an increasingly hip destination for budget travelers. But according to DJ Phil Tran, the best Vietnamese music comes from LA. "It's just like the music at home. But it sounds a lot better, because they use better equipment."

Boston still does not have a regular venue for Vietnamese pop, but whenever the city's Vietnamese students get together to dance, chances are Tran is laying down the grooves. One recent night, at the Wentworth Institute's Watson Auditorium, he played tunes by artists like Linda Trang Dai and the inimitable Elvis Phuong, whose bilingual version of "Unchained Melody" must be heard to be believed.

Tran's mix is heavy on the house music, whose torrid BPMs make it clear Vietnam is a tropical land. The slower numbers impart a stirring, almost Iberian cadence. Tran himself admits a special fondness for "the smooth, romantic sound" of the Vietnamese rhumba.

This is a real world-music phenomenon: Asian students in Boston, dancing to recordings made in Southern California. But you know, with the booming bass and the flashing lights, it doesn't feel like sociology. It feels like rock and roll.

Click here to read John Purin's Boston ethnic music highlights.