MANY MOVIES have been made in Philadelphia, but "Standing Ovation," which opens nationally today, may be the first since the original "Rocky" to be made of Philadelphia.

"You couldn't make this anywhere else," insisted writer-director Stewart Raffill during a recent lunch at the Fountain Room inside the Four Seasons Hotel. "The was the foundation - the boardwalks, the city, the characters, the land, the traditions the kids have grown up in, the accents . . .

"What's interesting is that this area is a quintessential All-American area. It's not like Hollywood, where kids from all over come to get into the movies."

Indeed, even "Rocky" - the iconic 1976 flick that put this city on Hollywood's radar - can't claim to be nearly as Philly-centric as "Standing Ovation," a "Rocky"-like tale with music. It's about the rivalry of two groups of performing girls - one polished and professional, the other a younger troupe far more ragtag, but filled with heart - vying in a national music-video competition.

Virtually everything (and everyone) in "Standing Ovation" is of local origin, other than Raffill (whose credits include directing the Wesley Snipes thriller "Passenger 57" and the sci-fi mystery "The Philadelphia Experiment"), executive producer and actor James Brolin, and some of the composers who contributed to the spirited, beat-heavy soundtrack.

Most of the film was shot at the Jersey Shore, the home base of celebrated vocal coach Sal Dupree, who acts in the film and served as the musical director. Several Philly locations also are in the mix.

Raffill's wife, producer Diane Kirman, who was the driving force behind getting the picture off the ground, is a Springfield, Delaware County, native with ties to Cape May, N.J. The entire cast is locally based (the kids who make up the bulk of the ensemble are Dupree's students), and the money to make the film was raised here: The lead investor was William Lewis, chief surgeon at Lankenau Hospital, who has an executive producer credit. Other localities also contributed.

Even the production-assistant corps had a distinct local flavor. It was made up of a group of South Philly women - including ex-People Paper staffer Jen Barkowitz - who, said Kirman, were nothing less than miracle workers.

"If you needed something, no matter what it was," she explained, "the one-word [response] you always got was, 'Done.' "

According to Raffill, the cast wasn't chosen based on a pre-written script. Instead, he let his actors' real-life personalities and idiosyncrasies dictate the characters' actions.

For instance, he spoke of Joei DeCarlo, a South Philly resident who brought her distinct way with words to the film.

One day, recalled the director who, despite decades in Hollywood, still speaks with a prominent British accent, he heard the young performer admonish someone on the set about his body odor.

"She said, 'You should take a shower, you smell like low tide!' I'd never heard that before. I thought, 'That's a good line,' so I put it in the script.

"These are characters from a different part of America, and Joei personifies that."

According to Brolin, that anecdote illustrates one of the charms of the old-fashioned-style musicale aimed at the 5 to 14 crowd. "Stu took the intrinsic part of each [actor] and made it bigger," he said.

That "Standing Ovation," which had a gala Philadelphia preview Tuesday evening at the Prince Music Theater, will open on some 1,600 screens nationwide is, in itself, something of a "Rocky"-style story. It is almost unheard of for an independent film with absolutely no known performers to get this kind of rollout, complete with national TV ads and talk-show hype (e.g. Brolin's Wednesday morning appearance on ABC-TV's "The View").

"We had Universal [Studios] execs watching it," he recalled, "and I could see them thinking, 'Wait a minute! How could this happen? How did they pull it off?' "

The answer, said Brolin, is that "Standing Ovation" is that rare film aimed at an audience the same age as the film's characters. For example, he pointed out that relatively few high school students watched "High School Musical," the Disney blockbuster whose main audience was 8- to 12-year-old tweens.

"If you do any research," he said, "you know that kids like to watch kids."

Brolin, Kirman and Raffill are confident they not only have a hit but, perhaps, the makings of show business' next big franchise. Brolin pointed to the reactions he observed among youngsters who have seen the film at screenings.

"The kids were texting during the movie," he said. Initially he found such behavior upsetting because he thought they weren't interested in what was happening on the screen. But he soon realized the kids were so into "Standing Ovation" they had to tell their friends right away by text message because "that's the new telegraph."

And speaking of screenings, Brolin's better half, Barbra Streisand, played an uncredited role in getting "Standing Ovation" off the ground.

"We held screenings at [the Brolins'] house," reported Kirman. "Barbra was always very gracious about it."

As they wait for the reviews and opening weekend box office numbers to arrive, the three partners have already decided to do a sequel, regardless of what happens over the next few days. They realize that even if the critics aren't impressed, the students who populate the nation's thousands of dance schools will probably see themselves in the film's characters and make it a rousing success.

And when "Part 2" does reach the screen, Raffill predicted, it won't share the original's "no-name" cast: "The kids will be stars by then!"