Il Divo has always had the big voices. Now on its fourth world tour, the quartet of operatic-style singers also has an appropriately big budget for stage design, lighting, video - and custom suits by Italian designer Giorgio Armani.

"It's a much more polished, much more engaging show," says American tenor David Miller, who will be performing with his cohorts - Spanish baritone Carlos Marin, Swiss tenor Urs Buhler and French pop singer Sebastien Izambard - at 9 p.m. Friday, July 3, at Borgata Hotel Casino & Spa.

That's not to say the experience of performing in an arena has gotten to be old hat.

"Everybody's work ethic is that it has to be at least 110 percent," Miller says. "We have gotten comfortable with arenas and people have gotten more comfortable with us. When we first went on tour, no one knew what to expect."

The initial confusion may have been due to Il Divo failing to fit an easy musical niche. The brainchild of Simon Cowell, the famously irascible "American Idol" judge, the idea was to create a vocal group that performed pop in an operatic style.

"It's not pop music - we're not strictly pop and are not popular enough to be played on the radio," Miller says. "We're using classical technique, but it's not technically classical."

Although the members lacked experience as an ensemble, each had done plenty of singing on his own. Marin and Buhler each had extensive classical credits, while Izambard had only done pop.

"He hired the four of us because of a certain chemistry (we) have, the way our voices blend together and because of our professional backgrounds," Miller says of Cowell. "(The idea was) it wouldn't be a boy band fresh out of high school, so he wouldn't have to mold and sculpt it into something."

The group, which has sold more than 22 million records, got its big break in 2006 when Barbra Streisand asked Il Divo to tour with her in North America.

"It was absolutely huge - the timing could not have been more favorable for us," Miller says. "We got to reach a whole corner of the audience market that wouldn't necessarily have come to an Il Divo show or hadn't heard of Il Divo."

Miller, 35, who holds a master's degree in opera theatre from Oberlin Conservatory and has sung leading roles with companies in Europe, Australia and the U.S., brings the heaviest operatic chops to the ensemble.

"It was a big adjustment," he says. "I had never sung with a microphone before. Singing in opera, you're almost projecting to the back walls. There's a certain dynamic level you can never drop under. Working with a microphone is a whole additional realm of using the voice that's previously untapped."

As much as he's enjoying this pop phase, Miller, who was to make his Metropolitan Opera debut when he joined the group, at some point plans to return to his classical roots.

"I'll be excited when the day comes that I will do more opera again - and the day will come," he says. "Opera isn't going anywhere … it may take a while before I get that invitation to come back to the Met. I will have to work my way up through the ranks and prove I'm still an opera singer."

For at least the next five years, he anticipates staying with Il Divo. He believes the group's current record, "The Promise" (Sony), which includes material by Frankie Goes by Hollywood, Leonard Cohen and Abba, among others, will be the blueprint for future musical outings.

"What we found was when we take songs and make them our own, it doesn't matter how disparate they seem," he says. "They will eventually sound like an Il Divo track. That's the point of departure for us. "

Il Divo at Borgata

WHEN: 9 p.m. Friday, July 3

WHERE: Event Center, Borgata Hotel Casino & Spa, Atlantic City

HOW MUCH: Tickets, priced at $75, $125, $150 and $195, are available at the Borgata box office or ComcastTix at 800-298-4200 or www.theborgata.com

WEB SITE: www.ildivo.com

What's Simon really like?

"American Idol" judge Simon Cowell can be as caustic behind the scenes as he is on the show, according to Il Divo's David Miller.

"He's very opinionated," Miller says of Cowell, who created the vocal group and still has a say in the material for its albums. "That, combined with a very dry English temperament, makes him look like an a--hole sometimes - you can't deny that. By the same token, when he gives compliments, they're just as dry. No one remembers when he says, 'That's amazing,' or 'You're going on to the next round.'"

Mostly, though, Cowell shows great respect for his hand-picked ensemble.

"With us, we're all on the same page - we're not competing with each other," Miller says. "We're still trying to work together to create something we can be completely proud of. He'll he honest with us, but he hired us because he likes us. There's never a moment when he goes, 'That's s--t' or 'That doesn't work.'"