Michelle Obama paid a visit Tuesday night to "The Tonight Show," her first appearance since she became first lady three years ago.

Though she was primarily there to promote her "Let's Move" initiative, Michelle did reveal a few enticing details about her marriage to President Obama.

"Did you ever think at this point in your life he would become a singing sensation?" Leno asked, referring to a video of the president's surprisingly good rendition of Al Green's "Let's Stay Together" that became a viral hit.

"I didn't even hear about it until it got on YouTube," she said. "But he does have a beautiful voice, and he sings to me all the time."

Michelle readily admitted that her husband has the better singing voice -- and knows it. "He doesn't hesitate to show off his lungs to his wife."

She also wasn't surprised by his song choice. "He sings a lot of Al Green, Marvin Gaye, a little Stevie. He likes the classics," she said.

Leno then asked Michelle whether she'd heard Romney's version of "America the Beautiful," which, even his supporters would have to admit, was not as mellifluous.

"It's beautiful," Michelle said, suppressing giggles. Then she got back on message. "It is America's song, and it's a song that's meant to be sung by every American."

Spoken like a true politician.

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— Meredith Blake

twitter.com/MeredithBlake

Photo: Michelle Obama appeared on Jay Leno's show Tuesday. Credit: NBC