ROCK / Que Guerra sera: Juan-Luis Guerra has opened Dominican music to the world. After him, the deluge?

ON Saturday, citizens of the Dominican Republic celebrated Independence Day. In the capital, Santo Domingo, the event was part of Carnival.

In Spain, Europe's largest concentration of Dominicans might have celebrated that their country's chief musical export of the Nineties is sitting at number two in the Spanish charts. Latin superstar Juan-Luis Guerra's fifth album, Areito, has sold 850,000 copies, a third of those in Spain, since its release in 1992.

Guerra and his group, 4:40, took two Dominican styles, the fast 2:4 merengue dance rhythm and the guitar-based romantic song bachata, and melded them, via his US Conservatory-trained jazz/rock sensibility, into a catchy, tuneful formula that took the Latin world by storm. Areito, two years in the making, follows the successful recipe - merengues; bachatas; Guerra's plaintive, pretty voice; poetic, slightly fey lyrics; and fashionable references.

If Areito has not as yet equalled the vast success of its predecessor, the five million-selling Bachata Rosa, it has still confirmed Guerra's status as his nation's biggest star, the man who broke merengue out of the Latin American audience. Of major world markets, only Britain, where Areito was released last week, has resisted the Guerra advance.

The Dominican Tourist Board issues posters now of the lanky superstar proclaiming 'Republica Dominicana - Tierra de Juan-Luis Guerra'. It is the land of much more besides, however, as a recent visit demonstrated. As is often the case, the further down-market you go, the more fun it is.

Saturday night. By the standards of merengue band leaders, Alfonso Vasquez Familia, normally known as Pochy, is a pretty sharp operator. By the standards of chartered accountancy, which was the profession by which he supported his early career, he is sensational. Since his newly formed 14-man Cocoband's first hit 'La Flaca' ('The Thin Girl') in 1988, he has performed continually (48 dances last December) and conquered record markets in Colombia, the USA and Germany. The Cocoband's formula has no trace of Juan-Luis Guerra's eclecticism; it's pure high-octane straight-ahead merengue. Animating a packed dance in a big school hall, the band churns out the rhythm inexorably. Sizzling, twitching cross-rhythms from the metal guro scraper and the double-headed tambora side-drum, tumbling frenetic jaleo choruses from the six-man brass section. The couples dance close, merengue-style, left hands entwined above their heads, upper bodies motionless. Afterwards, Pochy sits outside in his brand new silver Landcruiser, sipping beer, talking on the car phone, signing autographs for teenage girls, and looking like he's got bigger ponds in his sights.

Sunday afternoon. The latest Cocoband album, El Arrollador, currently at number 10 in the Billboard Latin charts, leads with a merengue, 'Pa' Los Coquitos' (For the Little Cocos), featuring a children's chorus. The sleeve depicts Pochy surrounded by beaming multi-racial tots. If this bears queasy implications of incipient Benetton-ism, move on rapidly to the work of Blas Duran.

Duran's records are not played on national radio. He doesn't care, he says, because they're rarely off 'Radio Duarte'. The slum quarter street named after the independence leader Duarte is home to Santo Domingo's main market, where dozens of cassette stalls blare out Duran's music constantly.

His speciality is double entendre of a simplicity which makes Benny Hill seem positively Wildean. 'El Conejo' (The Rabbit, carrying the same secondary meaning as the English 'pussy') is one of his biggest hits. The music of Duran's band, the Peluches (Teddy Bears) is similarly sparse and efficient, stripped down to an irresistably hissing guiro, rolling tambora, blasts of rough trombone and Duran's trademark, a repetitive treble electric guitar riff. An audience of working-class families at an open- air dance lap it up, filling the floor from lunchtime to dusk, when the band rushes off to another engagement. During a pause Duran, in purple suit, red shirt, crocodile patent shoes and kilos of gold jewellery, explains his sartorial policy. 'I dress elegant like this so that audiences will take me seriously, as a star.' Watch out, Juan-Luis Guerra and the world. Maybe.