Nightclubs around Washington seem to rise and fade in popularity with remarkable frequency, and there's always room for a new "in" place where club fans go to see and be seen on a weekend night.

Over the past few years, Mingles in downtown Washington, the Cornerstone at the Washington Convention Center, Seasons in Silver Spring and Joplin's at the Howard Inn are just a few of the popular nightspots -- each with its distinctive style -- that have enjoyed the word-of-mouth status as the new place for young black professionals.

Now comes Triples, a recently opened nightclub not far from the District's southern boundary in Hillcrest Heights that is named for its three floors set aside for eating, dancing and drinking.

Located across from the Iverson Mall shopping center, Triples also has a couple of new twists: a Cajun-Creole restaurant and a live jazz room, both included, the owners said, in hopes of attracting a throng of partygoing black professionals.

"I wanted an atmosphere where people could flow from one floor to the next," said David Sims, general manager of the 3-month-old club. "At most clubs people are confined and I wanted to break that monotony."

Some former customers say it is too unconventional, but Sims and his three business partners, Herb Fame, John Belk and Gerald Boyd, said they are unperturbed by that. Sims said the nearly $400,000 they spent to open the club was an investment aimed at the "sophisticated professional."

"We were looking for the middle-class blacks in the area who were 25 or older and basically had nowhere else to go when they wanted to party. We're tapping right into that market. So far, it's been a success," Sims said.

Sims, a former manager for the Mark IV club in downtown Washington that folded several years ago, and Fame were accustomed to taking chances.

Fame used to be half of the old Peaches and Herb singing duo that recorded romantic ballads in the 1970s.

While the two toured the country, Sims served as their road manager. It was during that time, Sims said, that he toyed with the idea of opening a club.

"I realized that in show business, things don't go on forever," he said. "When things started to slow down with the group, we decided to open the club. We were looking for something really huge. When I saw this building, I told Herb, 'I think we can do something with this place' "

Formerly a banquet hall for a nearby motel, the club is now an unusual mixture of a mellow jazz lounge with whirring ceiling fans, the candlelit Basin Street restaurant and three dance floors.

"I've always had this thing about blacks not knowing how to treat blacks at a restaurant with courtesy," Sims said. "We wanted to make people very comfortable and give them good service." The club employs about 60 waiters, busboys and bartenders wearing white shirts and bow ties.

"This is the best as far as live music," said District resident Renee Heard, 24, who was listening to music on a recent night at the club's Melody Lounge, a dimly lit room ringed with photos of Billie Holiday, Duke Ellington and other jazz greats. "I can mingle with anybody and enjoy myself here and not be harassed and hassled," she said.

A busy deejay pumps Top 40 music through a sound system to all three levels.

"I wasn't really hanging out anywhere before Triples because there wasn't really any place to go," said Tawana Cooke, 26, a bookkeeper from Hyattsville. "I like the older atmosphere and the older men here. I think men get more courteous after age 30."

Sims, checking details and troubleshooting throughout the club, said if business goes well, the club may add other elements next summer.

"You've got to keep changing your decor if you want to survive," Sims said, "and we plan on being around for awhile."