FRIDAY NIGHT is the last of this summer's four free "Weekend's Weekends" concerts at the Carter Barron Amphitheatre, sponsored by us folks in the section of The Washington Post you're reading right now. If you came to any of the previous shows, we thank you! You found out how wonderful a venue Carter Barron is for live music in the summertime, tucked away amid the trees of Rock Creek Park. If you haven't been yet, please come out Friday to hear a night of Latin music.

At 7:30 Mariachi Los Amigos begins the program, followed by two salsa bands: Orquesta Melao and headliners Orquesta La Romana. If this bill doesn't have you dancing in the aisles, we don't know what will.

Free tickets to the show will be released at the Carter Barron box office starting at noon Friday. The entrance to the amphitheater is on Colorado Avenue NW, just west of 16th Street. Gates open at 7. For more information, call 202/334-4748.

The scene every Thursday night at Cecilia's nightclub in Arlington (2619 Columbia Pike; 703/685-0790) is one of the liveliest in town. That's when Orquesta La Romana takes the stage and fills the room with its enormous sound. And that's when the crowd -- usually a couple of hundred people -- all start moving their feet (one-two-three-rest, one-two-three-rest) and shaking their hips to the salsa music the band is delivering so powerfully.

"I'm trying to emulate that Fania sound," says Edwin Ortiz, the band's leader and one of its percussionists. The 39-year-old Ortiz is talking about the legendary New York record label, founded in 1964 by Johnny Pacheco, that defined salsa through its releases by such artists as Willie Colon and Bobby Rodriguez. It helped formalize both the style and the name of the music (the term "salsa" was promulgated by Fania Records and others to help repopularize the music after the Cuban revolution contributed to a decline in its popularity in the United States).

The Fania sound is a particularly New York-based sound, one that Ortiz heard constantly as a kid. "I was in the Puerto Rican barrio of Manhattan," he says. "When I was growing up, I was hearing it, playing it, everything. It was the soundtrack to my life there. Orquesta Harlow, Willie Colon, Hector LaVoe, Pacheco. They were the guys."

He studied flute at Johnny Colon's music school in Harlem but was lured over to the percussion camp soon thereafter. "All the musicians who taught in that school, they used to sit and jam in the park in front of the school, and that's where I learned even more than just being in the school."

At 19, he decided with his wife that El Barrio was not where they wanted to raise their soon-to-be-born first child, and they moved to Washington. He immediately found percussion work in the area with Ramon Lara y Los Professionales and Orquesta Calidad, and in the mid-'80s he joined Pedro Julio Velasquez y su Nuevo Amanecer.

"He needed a conga player actually, and I'd been playing just bongos for years," Ortiz says. "But the limited conga knowledge I had got me over, and he hired me. From then on, he and I got along so well that he made me pretty much the manager of the band." When Velasquez retired and moved to Florida in 1989, he said to Ortiz, "You stay with the band. Keep it going."

There wasn't a lot of work for an authentic salsa band back then. That was the direction Ortiz wanted to take the group he'd inherited, but he knew he had to worry about getting enough gigs to pay the band if he was going to be able to keep it together. He noticed one thing about the local Latin music scene: merengue bands were getting all the work.

"Merengue is a Dominican music," Ortiz says. "La Romana is actually the name of a town in the Dominican Republic, and so I thought that by changing the band name to La Romana, we'd be hired by the clubs thinking we were a Dominican band." The ploy worked, and Orquesta La Romana was soon playing all the Latin clubs in the area, winning over the owners even after they'd realized Ortiz had subtly misrepresented the band. "I would never say we were a merengue band," he says, laughing. "I would just tell them the band name."

In 1994, Ortiz put the band on hold, frustrated by the difficulty in keeping an 11-piece band working steadily. But as he watched the Latin dance scene grow, he decided to relaunch La Romana, telling his band mates "there's no use coming back unless we're the best." The band rehearsed for a full year before its first public performance in 1997, learning new material and getting tight.

When they finally played in front of an audience again, it was to a packed house and Ortiz knew he would make it. "We played all night and didn't have to play a single merengue," he says. "They wanted the real salsa."

Now the band plays its old-school salsa frequently, making enough money at private parties to keep going. "We still can't quit our jobs, but we're doing pretty well right now," Ortiz says. And to keep its ever-growing fan base happy, there are the weekly gigs at Cecilia's. With several percussionists, a four-piece horn section and two superb singers, La Romana is an amazing sonic experience. The band features singers Mauricio Castillo and Willie Garcia, Ortiz and Giancarlos Rodriguez on percussion, Marciano "Cui Cui" Gonzales on congas, Marlysse Simmons on piano, Tony Laguer on bass, the father and son trumpet team of Tony and Marcos Alzamore, and trombonists Al Brevard and Herbie Martinez (who is also the band's musical director).

Cecilia's is the perfect place to see the band. The club has an enormous dance floor, dozens of tables where you can sit and order dinner and a 50-foot bar where you can watch the dancing couples make the most astonishing moves. "I was in New York recently," Ortiz says, "and I was looking at the dancers at places like the Copacabana, and I honestly think we have better dancers down here. I think we have better bands, too!"

I'm no expert on the New York salsa scene, but I'd say Orquesta La Romana can hold its own against anyone. Catch them at Carter Barron Friday or at Cecilia's on any Thursday and see if you don't walk away (or dance away) feeling the same.

Find out more at www.orquestalaromana.com.

* To hear a free Sound Bite from Orquesta La Romana, call Post-Haste at 202/334-9000 and press 8101. (Prince William residents, call 690-4110.)

Indira Terrazas and Avram Lubliner-Walters dance to Orquesta La Romana at Cecilia's in Arlington.Edwin Ortiz, left, Mauricio Castillo and the rest of Orquesta La Romana perform Friday at Carter Barron Amphitheatre.