More than 40 would-be restaurateurs gathered recently to hear Paul Cohn and Barry Silverman talk for three hours about how to open a successful restaurant. They came to the right place. In less than five years, Silverman and Cohen have opened four of the hottest restaurants in Georgetown: J. Paul's, the immensely popular bar and restaurant that, along with Clyde's, is one of the top draws for the young, with-it spenders who flock to Georgetown; Paolo's, one of the city's trendiest new Italian eateries; the River Club, the art deco dining, drinking and dancing spot for upscale adults; and the Georgetown Seafood Grill.

Paolo's, the Seafood Grill and the River Club all opened in the past year. "It's incredibly impressive that they've done so many concepts successfully so quickly," said restaurant consultant Mark Caraluzzi. "That takes an incredible amount of energy."

Energy crackles from Cohn and Silverman, as Silverman plays straight man to Cohn's mile-a-minute chatter. Cohn, a hip 46-year-old former rock-group manager with a diamond earring in one earlobe, comes up with the restaurant concepts. The quieter 32-year-old Silverman is the classic MBA type, with his navy blue blazers, gray slacks and an eye for the bottom line. He directs restaurant operations.

"I do the glitz, he does the business," said Cohn, who can still quote the numbers as quickly as Silverman at times.

Their advice to hopeful future restaurant owners includes: "If you're going to have a restaurant where people may have to wait, have a big bar where they can spend money," Cohn said. "Live the business; if you don't, you can't be successful," Silverman said.

Here's Cohn on getting financial backing: "Most businesses fail because they're undercapitalized. ... You can always find doctors and lawyers in this town who want to own a bar." Here's Silverman on watching costs: "A restaurant is like a big leaky bucket with a million little holes."

And from Cohn: "It's the closest thing to show business. ... You're on every night."

They practice what they preach. Each of their restaurants has a long bar at which patrons can gather to spend money while waiting for a table or just drinking. At J. Paul's, the "Cheers" atmosphere is firmly in place, with a classic 38-foot, saloon-type bar brought in from Chicago.

Cohn and Silverman took care of the important issue of financial backing for their growing restaurant empire when they sold J. Paul's to Capital Management and Development Corp. in 1984. They now develop and operate restaurants for CMDC, a real-estate development and management firm with offices in Beirut, London, Paris and Washington.

As for the show-business aspect of the restaurants, Cohn strongly believes that people want more than just food from a restaurant these days. That's why each of the restaurants is built around some key piece of movement or entertainment. At J. Paul's, it's the raw bar in the window that invites in passers-by. At Paolo's, it's the wood-burning pizza oven in the center of the room; at the River Club, the dance floor; and at the Seafood Grill, the open kitchen.

Part of the show at the restaurants developed by Silverman and Cohn is the help -- bartenders and waiters who serve up snappy repartee with the food.

But one restaurant industry observer claims the duo has "pirated employees from other restaurants -- particularly bartenders from Clyde's." Although a former Bartender of the Year from Clyde's works at the River Club, Silverman said he and Cohn do not go after other restaurant's employees. "They came to us," he said. "Because we're successful, we attract very skilled people."

Both Cohn and Silverman "live the business," spending long hours at the restaurants. Even when they travel, they're looking for new ideas and concepts. When the concept for Paolo's was being developed, they went around the country looking for the best pizza, winding up in New Haven, Conn., eating pizza at the famed Pepe's. And in the middle of a recent interview in their opulent offices over Paolo's on Wisconsin Avenue, Cohn snapped his fingers and told Silverman that he'd recently had some great duck pizza. "We need to put duck pizza in Paolo's," he said.

"I think they are remarkable in that they've managed to stay on top of what people want," said food consultant Ann Brody.

Each of the restaurants pinpoints a specific audience or niche in the market -- and each has obviously hit the target, judging by sales figures. According to Heinz Stiehl, president of the hospitality division of CMDC, J. Paul's 89 seats account for more than $3.5 million in sales each year, with projections for the newer restaurants at $3.5 million annually for Paolo's, $3 million for the River Club and $1.5 million for the Seafood Grill.

One restaurant observer who asked not to be identified called the concepts "derivative rather than creative," mentioning Clyde's as the leader in the local restaurant-yuppie bar field. But other experts said that while Clyde's has been doing the same thing for years, CMDC is trying new ideas.

Cohn and Silverman discount Clyde's -- with seven local restaurants and plans for three more -- as their chief competition. "They're competing with us," Silverman said. "We've changed the market." They say they'd most like to be compared with Lettuce Entertain You Enterprises, the Chicago restaurant empire that has consistently introduced successful new restaurant ideas.

"Basically, they have got the Washington youth market figured out," said Robert Shoffner, restaurant critic for The Washingtonian magazine, who calls some of Silverman and Cohn's concepts "gimmicks" and has not always given the restaurants good reviews. But he admits that these are two smart businessmen.

Cohn got into the restaurant business in 1983, when he spent $150,000 in cash from his rock-and-roll days to buy Wall's Grill, an M Street power-lunch steak place that failed despite its prime location.

Cohn spent more than $500,000 to turn Wall's into J. Paul's. He knocked out the walls, opened up the large front windows and brought in the long bar. But as he now admits, he knew more about concept than food.

That's where Silverman, a political science major who worked his way through college in the restaurant business, came in. Silverman, who had been a partner in J.J. Mellon's downtown restaurant before a falling out with the other owners, walked into the yet-to-be-opened J. Paul's and told Cohn he didn't know what he was doing. Silverman went to work on a salaried basis with the understanding that "after a month he'd either let me go or I'd be a partner." They've been partners ever since.

Not that they always agree. When Cohn decided to put the raw bar in the front window of J. Paul's, Silverman "fought and kicked and screamed. ... My food expert," said Cohn, rolling his eyes.

Silverman, who keeps an eye on the money -- and on Cohn when he's giving away expensive bottles of champagne -- was skeptical, too, about the River Club, which cost $1.3 million just to outfit in a classy, art deco look. Yet critics have loved the supper club's food, and many local hotel concierges recommend it to out-of-town guests.

The restaurants are financed internally by CMDC with profits from previous ventures, relieving them of the debt-service worry that hangs over many restaurants. The company intends to continue to grow that way -- rather than through franchising one of its ideas. That may not enable it to grow as quickly as some other restaurant groups, Stiehl said, but it gives the company fewer money worries and more control over quality.

Silverman and Cohn said they have a strong commitment to the Georgetown area, with the company's four present restaurants within blocks of each other in the high-pedestrian-traffic zones of what Shoffner calls "Washington's playground."

"They learned Georgetown well, studied the demographics," Brody said of J. Paul's and Paolo's. "It's unusual -- picking a dense area and making a position to stay there with different concepts."

The concepts are the lifeblood of the restaurants and, now that they're in place, CMDC will begin to branch out from its base. In May, a J. Paul's will open in Atlanta, and the company is looking for a Rockville location. They are also considering a catering operation, said Silverman, who added that they are always looking at several things.

But what's important is keeping an eye on what's already there, Silverman said. "We want a steady, firm foundation," he said.