Kid Rock rocks the house for Mitt Romney

ROYAL OAK, MI - For months, the Romney campaign has been rolling out endorsements from every prominent politician and business leader it can get its hands on. Tonight, Romney got an actual rock star.

Surprising an enthusiastic crowd of over a thousand people at the Royal Oak Music Theater, Kid Rock - one of Michigan's most famous musicians - performed his hit, "Born Free," which has become Romney's campaign theme song.

The song debuted on the trail with Romney in early December in Arizona, and it plays on repeat at almost every single Romney event.

Romney himself revealed his mystery guest tonight, saying, "I'm happy to introduce a son of Detroit, a friend, a guy who makes great music who introduces me everywhere I go: Kid Rock!"

(Watch Kid Rock perform "Born Free" for Mitt Romney.)

At first glance, the pair make an unlikely duo: Romney is the strict Mormon who plays up his conservative values, while Kid Rock is the tattooed and rambunctious celebrity with more than a few songs celebrating his wild side.

The two met on Thursday at Kid Rock's home, after Romney returned to Michigan from Arizona.

According to a campaign aide, they spent an hour together, and discussed topics of shared interest to the two: commitment to country, Detroit, and the troops.

Romney asked Kid Rock if he would perform a "closing song" at this event, and the next day, the two exchanged personal emails, where Kid Rock confirmed he would join.

Romney shared parts of the encounter tonight.

"He had a piece of paper in front of him. He had some questions for me. He said, 'First off,' he said, 'Mitt, if you're elected president, will you help me help the state of Michigan?' I said I would. He said, 'If you're elected president, will you help me help the city of Detroit?' I said I would," Romney recalled. "And then I turned to him. I said, 'By the way, given the fact I'm willing to do those things, would you be willing to come here and perform a concert tonight for my friends?'"

The night was not all raucous rock, however. Before the musical performance, Romney delivered strong words for the Michiganders on hand and looked ahead to the general election.

"I think the reason that I'm going to beat Barack Obama in Michigan this fall is because this is going to be a contest about who can strengthen the economy," Romney said. "And we'll look at his record, and it's been a failure. And we'll look at my record, and the successes I've had, and I'm going to be able to talk about the economy with great ability he doesn't have.

"And my commitment to getting America working again will be second to none," he continued. "And for that reason, I'm going to win in Michigan, and I'm going to win across the country."

Romney, however, is be no means the presumptive nominee here.

"To get to that spot, of course, I've first got to be the nominee," he said. "I need you guys to get out and vote tomorrow, get your friends out and vote."

Ann Romney, who stood by her husband's side tapping her feet and clapping her hands during Kid Rock's performance, also played up her Wolverine State roots. She praised Romney as a leader who could fix Washington.

Touting her husband's record of turning around the Olympics and businesses, she said, "In everything he's done, he's done it with excellence, integrity, and just success in everything he's done. That's what we need to have happen in Washington. I'm ready for some sanity to be brought back to Washington, can't wait to see this guy do it."