By Stacy Jenel Smith With her 12 and nine-year-old sons Nat and Alex suddenly hitting the big time as stars of Nickelodeon's "The Naked Brothers Band" juggernaut, Polly Draper admits, "It's definitely giving us pause - a lot of pause.

"It's not going to be bumpy, it's going to be explosive," she goes on. "Everybody kept saying, 'Don't worry, it'll be a lark. When Nickelodeon first asked us about doing a series, we said, 'How about a cartoon, so the kids can stay normal?' They said, 'No, we love your kids.'"

And after all, "Most of these things don't go anywhere," reasoned many around Polly and her husband, celebrated jazz musician/composer Michael Wolff ("The Arsenio Hall Show"). "But sure enough...."

"The Naked Brothers" took off, rocket style, after its February launch as the highest-rated series debut on the channel in seven years. That was in the wake of multiple showings of the "Naked Brothers Band" 2005 mockumentary movie that writer-director Polly made (with cameos by friends like Julianne Moore, Tony Shalhoub, Arsenio Hall, Uma Thurman and Polly's former "thirtysomething" cast mates) and showed at the Sundance Festival. Nickelodeon toppers loved the Beatles-esque film, saw a series in it and now, obviously, the show has taken the whole enterprise to an entirely different level.

It all started after September 11, 2001, when Nat had a birthday party at a fire station, and "said he wanted to do a benefit for the firefighters' kids with his band. He had this band, and he was like six years old. It turned from being a cute idea to an event that raised $45,000. We had 300 people who came to the house to watch it, and our next door neighbors let us use their house. Alex was three. He was going to play shakers in the band or something, and when it came to Alex's solo he said 'I have the hiccups and I have to go potty.'"

Two stars were born.

Other benefits followed. Polly says, "a lot of it's driven by Nat's music. It's like a force of nature, propelling this whole thing."

Her mockumentary began as "a glorified family movie, something the kids would enjoy doing." With other family members involved, including cousin Jesse Draper, who also costars in the series, pretty soon the Draper-Wolff clan was tantalized by the idea of doing the movie "for real."

Then came the star friends. "Julianne (Moore) was the first one to shoot a scene in it. She had to go away to do a real movie," Polly recalls. "I said, 'If you were in it, it would lend some credibility to the idea that Nat is a star. Can you do it Thursday?' And she said yes!

"We found this building and put a couple chairs in it, and made it like the backstage of a talk show, really funky - like New York talk show green rooms really are. She and Nat both did it in one take. He was surprisingly great. I thought, 'Wow!' He's really good at this acting thing.'"

Critics and fans thought so too.

Draper, who directed all the episodes of the series in addition to the movie, recently completed post-production on the first set of shows on which Wolff plays his sons' musically-inept father on the show.

"My husband and I have some degree of fame ourselves, but it came at a later age," notes the actress who remains fondly remembered as Ellyn Warren of "thirtysomething."

"This is going to be challenging for the boys. I don't think they have any sense of how challenging it's going to be." The family has already had to change phone numbers due to an onslaught of calls around the clock from Nat's and Alex's adoring young fans.

"Little girls would call and say, 'Helloooo, is Matt there? We just love him," she coos in a child-like voice. "The only thing that's comforting is, they're pretty harmless at that age," Polly notes.

An array of merchandising tie-ins are in the works for the boys, who named their band on a bath day back when they were little kids. "Naked Brothers Band - The Movie" is soon to be released on DVD with video extras, and a CD is also on the way. There are no worries about radio; Nat and Alex's ' "Crazy Car" song became a a top-50 download on iTunes "with no air play."

Where Polly and Michael are drawing the line is touring - for now. "There have been a lot of people asking for the boys to tour, but they're too little. The band isn't ready, though they will be."

She says that at this point, Nat and Alex "seem to be taking it in stride. I think they always thought they were famous." The young singer-songwriters have been doing their musical thing for years, playing quite a few big ticket benefits. So they're used to attention from girls who try to grab their legs. "It's like, 'The girls are grabbing onto our legs, what else is new?' It makes them sound arrogant but it's really sort of the opposite," insists Polly. "They put more stock in the doing of the thing than the results. I think that's the coolest part."