Long-haired Chilean rockers belted out Lou Bega's hit song "Mambo No. 5" on an outdoor stage, dazzling the several hundred people in the main square of this small central Chilean town. "You and me gonna touch the sky," they crooned, preparing the crowd for take off. After the warm-up band finished, the headliner rocketed to the stage.

But it was no musician. It was Joaquin Lavin, 46, a Yuppie-looking economist who is becoming the most viable presidential candidate Chile's right wing has fielded since Gen. Augusto Pinochet's 17-year dictatorship ended in 1990. In the months before Sunday's elections, the University of Chicago graduate, who shuns suits for casual pants and pullovers, has set out to reinvent the intolerant, stodgy and elite image of Chilean conservatives--making himself a serious contender in the process.

In a country where the right wing was defined by hard-liners such as Pinochet and his wealthy supporters, Lavin has portrayed himself as a hip but humble family man born outside the aristocracy that forms the power structure of Chile's conservative wing. He is using rock concerts and other friendly gimmicks to distance himself from the brutal image of the military regime he once supported. And he has gone as far as praising a Chilean judge who is pursuing civil charges against Pinochet. The former leader is being held in London awaiting extradition to Spain for a trial on crimes committed during the dictatorship, including the killings of Spanish citizens.

Lavin has struck a chord by blazing through this nation like a Spanish-speaking Ross Perot, railing against government waste and inefficiency. Breaking tradition, Lavin has campaigned in conservative Chile's no man's land--poor neighborhoods where he has sometimes been welcomed, but is sometimes met with hostility. His strategy, analysts say, has been to combine his message with the nationalistic populism of such successful Latin American leaders as Peruvian President Alberto Fujimori--though, like Fujimori, Lavin also tends to gloss over important social issues, such as censorship and the need to strengthen democratic institutions.

"These labels, 'the left' and 'the right,' they mean nothing today," Lavin said at a recent political rally. "I'm talking about an end to politics as usual. . . . The rich people [don't need change], they are taking care of themselves. . . . The ones who need change are the poor, who need dignity; the unemployed, who need jobs; the young, who need a future; and the retired people, who need higher pensions."

Opinion polls indicate that Lavin's strategy--coupled with a campaign war chest some analysts estimate at $40 million, far more than those of the other five candidates combined--has worked. Lavin has sliced a double-digit deficit to front-runner Ricardo Lagos to 3 to 6 percentage points. But most political analysts say it is unlikely any candidate will win the majority needed for a first-round victory, most likely sending Lagos and Lavin into a run-off next month.

This year, Lagos's Socialist Party--the left wing of the Concertacion coalition--easily won the group's primaries for the first time since democracy was restored. Frustrated with growing inequality under the leadership of the Christian Democrats, the Concertacion's centrist party, Chileans have warmed to Lagos. A veteran dissident of the Pinochet era, the 61-year-old Lagos has pledged a moderate brand of socialism similar to British Prime Minister Tony Blair's programs to bridge the gap between the rich and the poor.

Lavin has promised a similar focus on inequality but has done so in a much shrewder way, analysts say. "Lagos is out there talking about complicated concepts like deepening democracy while Lavin is out there promising schools and roads," said Ricardo Israel, director of the Center for Political Studies at the University of Chile. "Lavin has borrowed from the style of Fujimori . . . and it's worked with more voters than many people thought."

While maintaining a progressive economic focus, however, Lavin has remained socially conservative. He is a member of the staunch Catholic organization Opus Dei and is against legalizing divorce in Chile--the only Latin American nation where it is outlawed.

Though Lavin has tried to paint the Pinochet issue as "something from Chile's past," he has nevertheless been forced to discuss it. During the military dictatorship, Lavin was a rising political star. One of the "Chicago Boys" of Chilean free-market economists who emerged from the University of Chicago's School of Economics in the 1980s, he worked for the government briefly as a minor economic adviser. Later, he was an editor at Chile's right-leaning El Mercurio newspaper, where "there's no doubt he was part of the propaganda machine of the dictatorship," said Carlos Huneeus, a Santiago-based political analyst.

But to underscore what his supporters call Lavin's "evolution" in political thinking, when addressing the issue of putting Pinochet on trial if he returns to Chile, Lavin has said "no one is above the judicial system, regardless of their last name."

His lack of public support for Pinochet has angered the hard-core right, though they say they will vote for Lavin anyway. "Lavin is a politician of the 21st century," said Alberto Cardemil, president of the rightist National Renovation Party. "He stands for the people who are both in favor and against Pinochet."

But Lavin's liberal opponents have called his views politically opportunistic.

"When it was in fashion to support Pinochet, Lavin did, and now that it's no longer in fashion, he has decided not to support Pinochet," said congresswoman Isabel Allende, daughter of former president Salvador Allende, the democratically elected Socialist who was found dead after Pinochet's 1973 coup. "At the time when he is running for president, it seems very convenient, does it not?"