Alan Jackson and Craig Campbell played at the Stars Go Blue concert Wednesday (March 20) to benefit the fight against cancer, a very personal battle for both artists. Craig lost his father to the disease, and Alan walked through his wife's successful bout with it.

But the two artists—who share a producer, Keith Stegall—aren't exactly besties. Yes, Craig has opened for Alan, but, Craig told reporters, "He's very mysterious. You never see him until it's show time."

Still, Craig said, he did ask for and receive an audience with the country legend before the first show they did together.

"When I walked on his bus, we was talking a minute, and then he's like, 'Keith played me your album. I love it,'" Craig said. "And then he started naming off songs off my record. I just thought that was the coolest thing."