"That would certainly be an apt description," said Sal Clemente, musical director, vocalist and co-founder of the group that tonight kicks out the jams at the Atlantic City Hilton. Apt, because the Boston-based URO uses the talents of 13 - count 'em, 13 - singers, backed by five musicians, as it offers faithful renditions of rock anthems by such titans as the Beatles, David Bowie, the Who and Queen.

Officially chartered in 2006, the band's roots date to 1999, when Clemente and drummer Alan Ware decided to develop a concert version of Andrew Lloyd Webber's groundbreaking 1970 "rock opera," "Jesus Christ Superstar."

"I felt like every other interpretation out there lacked any kind of rock-'n'-roll sensibility, that it had been corrupted by musical theater groups," he explained. "But it's very much a rock-'n'-roll piece. The original version had [members] of Joe Cocker's group."

Clemente and Ware worked for years on the project and finally booked a Boston venue. A band was assembled, tickets were sold. Then Webber's lawyers got in the act, legally preventing the live performance of more than five songs from "Superstar."

"To fill out the rest of the night, we decided to play songs that never got played live, songs that could have been in rock operas," Clemente recounted. "When we played that stuff in front of people, they lost their minds. We said, 'I guess we're onto something.' "

While it's true that tunes like the Who's "Won't Get Fooled Again" and Bowie's "Ziggy Stardust" have been in-concert staples for the artists for decades, Clemente is especially proud of the pieces - e.g. the Beatles' "Sgt. Pepper's Lonely Hearts Club Band" - that have never received live airings by their creators.

Even "Bohemian Rhapsody" is done in a way Freddie Mercury and company couldn't achieve. "They never performed [the song] live with the vocals," he said. "Even Queen used tapes."

Clemente noted that URO is not necessarily interested in painstakingly recreating every note in the manner of Montreal's the Musical Box, which virtually clones concerts performed by Genesis during the era when Peter Gabriel fronted the band.

Clemente pointed out that would be impossible, considering six of the band's vocalists are female, and most of the material was originally sung by males.

Besides, he added, "As much as I love Freddie Mercury, the thought of getting onstage in one of his leotards makes me want to vomit."

Instead, he offered, the group "is rooted in the spirit of these bands as much as possible." He attributed its success thus far (URO just completed a six-month weekly residency at a Boston theater) to the band's ability to create a "great sensory experience" enhanced by a massive light show and an energetic membership he described as "18 people jumping around like maniacs for two hours."

According to Clemente, URO is finding unexpected favor among a group that simply didn't exist when the music it plays was being created.

"It sure is a much wider [audience] than we ever thought it was going to be," he said. "We thought it would appeal to people 35 and up, but we find we have a huge age span. There are people bringing their 6-, 7-, 8-year-olds. And teenagers freak for us.

"It strikes such a nerve for these people to hear this music in three dimensions. And there's no comparable music today."

Atlantic City Hilton, Boardwalk at Boston Avenue, 9 tonight, $25, 800-736-1420, www.ticketmaster.com. For more on URO, go to www.anatro.com.

50 reasons to party

There will be a cover charge. People under 21 will not be admitted.

Chuck Darrow has covered Atlantic City and casinos for more than 20 years. Read his blog http://go.philly.com/casinotes.

E-mail him at darrowc@phillynews.com.

And listen to his Atlantic City report Saturdays at 1:25 a.m. with Steve Trevelise on WIP (610-AM).