Christina Aguilera, Cee Lo Green Sing 'Crazy' In 'The Voice' Preview

Extended sneak peek of reality singing competition aired before Thursday's 'Tonight Show.'

It's been almost impossible to avoid the avalanche of promotion for NBC's new reality singing competition, "The Voice." From splashy magazine ads to endless TV promos and interviews with the show's four celebrity coaches, the show has been getting a full-court blitz in the lead-up to Tuesday night's premiere.

The biggest push to date occurred Thursday night, when a 12-minute teaser aired before "The Tonight Show,"

highlighted by an all-star performance of the Gnarls Barkley smash "Crazy" by the four judges. With Maroon 5 singer Adam Levine on drums, country star Blake Shelton on guitar and Christina Aguilera and Cee Lo Green adding their pristine vocals to the song that made Green a superstar, each member of the quartet brought their patented brand of star power to the pop summit.

Aguilera, of course, indulged in some of her R&B diva melisma, Green his deep soul growl, Shelton a bit of country grit and Levine some surprisingly sharp drum chops. The studio audience went crazy as host Carson Daly explained the unique concept behind the show, which will have the coaches listening with their backs turned to singers vying to be their protégés.

With no clue as to how the singers look or dress or how old they are, Daly said the coaches will have to focus only on, yes, "The Voice."

"I'm drawn to very soulful, bluesy type voices," Aguilera explained, while Levine said he doesn't care if you're a country, pop or R&B singer. "I won't know until I feel it," Cee Lo said.

Here's how it works: If a coach likes what he or she hears, that person hits a red buzzer and the words "I want you" light up on his or her giant red captain's chair, making the singer part of that coach's team. But if more than one coach hits the button, then the artist gets to choose which star to work with and he or she can pit the professional singers against each other. If no buttons are hit, the singer is sent home.

Once the teams are set, the coaches will begin working with their charges leading up to a battle round where they have to cut their teams of eight in half. The final performance rounds will have viewers at home picking a winner.

The rest of the preview consisted of a sneak peek at some of the blind auditions, including a country singer who earned high praise from Green and Shelton and an offer to go pantless from Aguilera. It gave a look at the banter between the judges and the friendly competition between them to land the singers. "Man, if you weren't six-foot-five I would kick your ass," Levine joked to Shelton after the country star sassed him for turning around.

What did you think of the preview of "The Voice"? Let us know in comments below.