In truth, very little - except they all are playing under one roof tomorrow evening at the fourth annual globalFEST, a spectacular world-music concert that brings together some of the finest (if virtually unknown here) international performers.

GlobalFEST is this city's - indeed our country's - premiere world-music event. Over the course of its four-year existence, it has grown from a single night at the Public Theater in 2004, to a two-night event in 2006, to tomorrow's concert held for the first time at Webster Hall, effectively doubling audience capacity. The festival brings together 12 musically and culturally disparate artists from across the planet performing on three stages, and sure to blow the minds of aficionados and neophytes alike.

So, why should a fan of contemporary pop music or classic rock - say Jay-Z, Led Zeppelin or Justin Timberlake - lay down hard-earned ducats for a night of relatively obscure world music?

"Artists all over the world are listening to those bands and incorporating their music into their own," explains Bill Bragin, director of Joe's Pub and globalFEST's co-producer, along with Maure Aronson of Boston's World Music/Crash Arts and Isabel Soffer of the World Music Institute.

"If you like Led Zeppelin, check out Tinariwen - one of Robert Plant's favorites. If you like Dave Matthews, try Lenine. Nuggets-era '60s garage rock? Try Dengue Fever. Love Jay-Z's flow? Try Dara J."

Many artists have received big offers after playing globalFEST. The Portuguese fado singer Mariza went on to play Carnegie Hall. Vusi Mahlasela, a South African singer, played with Dave Matthews and signed to his ATO label. Groups like Beat the Donkey, Balkan Beat Box and Forro in the Dark became major presences on the world music circuit.

Expect the same from tomorrow's lineup, which spans continents, cultures and dance moves all while speaking a universal language certain to stir souls and melt hearts.

What follows are four hot acts to keep your ears open for - both tomorrow night and beyond.

Babylon Circus, Lyons, France

"GlobalFEST will be the first time we have played the United States," says an exuberant Ben Herbiere, manager of the rollicking 10-piece French band Babylon Circus. The band has sold more than 100,000 albums and played more than 1,200 shows across Europe and North Africa.

The group features two singers, traditional instruments and a full-on horn section and plays a high-octane hybrid of Eastern European folk and Gypsy music combined with ska, jazz, dub, punk and even Celtic music. They are often compared to frenetic New York Gypsy punk band Gogol Bordello. The band even attended a circus school to make its live show even more crazed.

Recommended: One of their best-known songs, "J'aurai Bien Voulu" ("I Wish I Could"), is a jaunty, jazz-era ballad from the band's 2004 album, "Dances of Resistance," its best-known work. You can download songs and see videos on their official carnival-like home page, babyloncircus.com, and on their MySpace page, MySpace.com/babyloncircus.

Lenine, Recife, Brazil

"My roots are in Brazil, but my antennae are everywhere," explains Brazilian pop sensation Lenine (pronounced Leh-NEE-nee). The singer and guitarist with a raspy, warm baritone combines the traditional music of his native northeastern Brazil with rock, pop, funk, hip-hop, electronic and jazz music.

His biggest influences, he says, are "the Police and Led Zeppelin." Last year, he swept Brazil's TIM awards with an MTV Unplugged album and won two Latin Grammys. He will be playing an acoustic set at globalFEST.

Recommended: A self-titled compilation featuring his best songs has just been released on Six Degrees Records. Standout tracks include the funky and percussive "Jack Soul Brasileiro" and the haunting ballad "Paciencia." Both are available on his MySpace page: MySpace.com/leninemusic. Sound clips and more information are on his official site, lenine.com.br/

Carolina Chocolate Drops, North Carolina

"The definition of world music depends on what country you're sitting in," says Bragin. In this case, the three 20-something African-American musicians are sitting on the front porch in North Carolina carrying on an antebellum American music tradition of banjo and fiddle from the Carolinas' Piedmont region.

The band plays every Thursday with their mentor, octogenarian fiddler Joe Thompson of Mebane, N.C, said to be the last black traditional string-band player. The Drops' accomplished picking, bowing and tight harmonies will send chills up your spine.

Recommended: Their debut album, "Dona Got a Ramblin' Mind," is on the Music Maker Relief Foundation label, which also provides assistance to traditional musicians in need. Standout tracks include the knee-slapping "Sourwood Mash" and "Georgie Buck," and the mournful "Short Life of Trouble," available on their MySpace page along with a video that helps explain the band's music tradition: MySpace.com/carolinachocolatedrops. More information at sankofastrings.com/ccd/contact.html.

DENGUE FEVER, Los Angeles

"At our show in San Francisco we had about nine Cambodian hip-hop thug guys start break-dancing in the middle of our set," says Dengue Fever's drummer, Paul Smith.

Given the funky drums, the '60s psychedelic garage-rock and surf sounds, and the alluring, vibrato-heavy vocals of stunning Cambodian singer Chhom Nimol, spontaneous break-dancing shouldn't come as much of a surprise. The band's pedigree also includes members who played with Beck, Brazzaville, the Radar Brothers and Dieselhead.

Recommended: Their second album, "Escape From Dragon House" (M80/Birdman Records), is considered by some to be one of 2006's best. Standout tracks include the funky and driving "Sni Bong" and the opium-den backing track "Sleepwalking Through the Mekong," both available on MySpace at MySpace.com/denguefevermusic. More information on the band at their official site, denguefevermusic.com.