By Stacy Jenel Smith They share the same manager as Christina Aguilera. They've been wowing testosterone-heavy crowds singing the national anthem at sports events. They're gorgeous blondes. They have a much-anticipated tour coming up, and have gained avid fans by way of a TV special. Sasha Lazard and Shawna Stone are on their way up so fast; you'd almost think they were a pop music act.

In fact, they're classically-trained vocalists who've performed in some of the world's most respected venues for opera.

The latest hot entry in the "popera" arena that's been so good to the likes of Josh Groban and Andrea Bocelli, the pair is breaking out thanks to their newly-released Manhattan Records EMI album, "Siren," and recent "Heavenly Voices" PBS special with Ryland Angel and Giorgia Fumanti. This summer they'll go out with Angel and Fumanti on the Heavenly Voices concert tour across the country. International dates will follow.

"A big goal of ours is to broaden the operatic demographic," says Shawna, who points out with pleasure that her and Sasha's set list is diverse, to say the least. "Nobody would imagine that there would be a Radiohead song on the first track," she notes of their rendition of "Fade Out."

"When people hear it, they appreciate that the song is such a dense song and so orchestrally-driven, it really did lend itself to opera." The album also includes Sting's "Fields of Gold," James Taylor's "You Can Close Your Eyes," and Johann Sebastian Bach's "Air on the G String," to name a few.

Speaking of G strings, Shawna is the half of the team who did the jaw-dropping photo spread wearing very skimpy lacy lingerie in FHM magazine - further evidence that this ain't your grandpa's soprano.

Shawna is also the one from Fremont, California, who knew by age six that she wanted to be a singer - and started funding her own voice classes at age 10 by teaching neighborhood kids how to play the piano. She eventually was granted a full vocal scholarship by USC, from which she earned a degree in opera.

"The training never ends," she says. "I still take voice lessons, still have coaching" - especially for the grand opera she continues to perform despite her current foray into the mainstream.

"The training is intense, to be a very good singer and have a healthy voice for the duration of your career. A couple people told me last night, 'Oh, you're so lucky to have such a beautiful voice.'" She laughs. "Lucky? You have to have some natural instinct and passion for it, but it's learned. They say luck is when opportunity meets skill."

Sasha is the one from New York City's Upper West Side, who grew up partly in Paris; her father being French and mother American. She adored opera from a young age as well, joining a choir at 12 and beginning vocal training at 15. She studied literature and voice at the San Francisco Conservatory of Music, and got to be friendly with musicians from the rock world. She joined a rock band herself, in fact, and pioneered fusing her classically trained voice with electronic dance music. She released her "The Myth of Red" album in 2002.

And Sasha is the one whose wedding to film producer Michael Mailer - son of Norman Mailer - was featured in Harper's Bazaar as one of THE social events of its season. Her and Michael's home got its own spread in House & Garden magazine. According to the New York Post she doesn't like to be called a socialite. Now she can be called "Mom," since she has a baby son.

Brought together by their record company and shepherded through the "Siren" creation process by no less a producing titan than Grammy winner Peter Asher, they now proudly share such critical superlatives as "groundbreaking."

When Sasha and Shawna performed Gaetano Donizetti's "Una Furtiva Lagrima" at their "Siren" CD launch party, their manager, Dave Lory, admitted he found himself feeling emotional. - and went around telling other guests the song was his favorite part of the performance and "I'm a convert. I can't believe I'm a convert!"

That's according to Sasha, who says that in the past, Lory has been "among those who have no interest in the opera world. His eyes would glaze over when he talked about it," she notes with amusement.

He's also the one responsible for booking them into national anthem gigs at Mets and Braves games.

In fact, the Donizetti piece alone could win converts. Sasha recalls that "recording it was an interesting experience. "We recorded two songs live in Air Studios in London. Peter Asher, our producer, was inspired to have us do them at two a.m.. We were exhausted. I was seven months' pregnant. I hadn't eaten in hours, and there was nowhere to get food at that time in the morning."

If the song makes listeners "think of being very hungry, that's why," says Sasha.

She adds that her son "was a big source of inspiration throughout the making of the album, the whole process."

Now he's traveling with her. "He's happiest when he's around a lot of people," she notes. It's a good thing, with his mother's lifestyle.

Sexy Shawna. Rich Sasha. Whatever you call them, they sound like angels.