A sign of just how long ago Mason Jennings met Jack Johnson: Both singers were opening for Pete Yorn at Gustavus Adolphus College in St. Peter, Minn.

"I walked off stage, and he was just standing there saying, 'Man, keep playing,'" Jennings recalled of the 2000 encounter. "I didn't know who he was. He doesn't look like a musician at all, you know, he looks like some buff jock guy. So I thought it was kind of weird."

Johnson remembered, "I sat there for one of his songs and then decided I wanted to hear the next one, and eventually I settled in for the whole set. I was blown away."

Eight years later, Johnson is one of the biggest stars in music, and Jennings' new disc, "In the Ever," came out last month on Johnson's Brushfire Records. The Minneapolis singer/songwriter will tour with Johnson through the summer, landing Sunday at River's Edge in Somerset, WI. But both singers insist they're friends first.

"He's just one of those guys I like being around," Johnson said. "We both met during that time when we were trying to get our things off the ground, but our friendship wasn't rooted in that at all. And our conversations still never have anything to do with the music business."

"I think it's so amazing the kind of music he puts out is so popular," Jennings said. "He sings so quietly, and it's just sort of this kind, positive music, and it's No. 1 in, like, 15 countries. It's strange to watch someone you know get that famous. But with him, it's extra weird because he's always been like, 'Oh, I'm just a surfer.'"

Jennings' career has developed more gradually. He garnered a small but dedicated audience and scattered critical acclaim with self-released albums. In 2006, he wound up on Epic Records for his last disc, "Boneclouds," but it wasn't the right move, Jennings said: "The label was too big and the people were more suited to do acts like Shakira and the Fray."

For "In the Ever," he bought a cabin about 45 minutes from Minneapolis, where he could work in solitude. The new disc harks back to Jennings' earlier, rawer albums and is almost entirely acoustic. The new song getting the most attention -- thanks mostly to Johnson, who has been singing it on tour -- is a simplistic and even goofy gem called "I Love You and Buddha Too," which name-checks Jesus, Buddha and other deities in a plea for religious tolerance.

Johnson said, "There are other songs on this record that I probably love more, but that's the one we sing around the house. Even my little 4-year-old sings it. It's a good kids' song. It has a positive message that the whole world should hear right now, yet it's simple enough for kids."

Johnson knows firsthand, though, that there can be a downside to working under another singer's shadow. "Ben Harper and G. Love were both fans who gave me a big push early on," he recalled. "The first year or two after that, every interview I did was asking about those guys. I really appreciate that connection, but it was nice when it split off into my own thing."

For now, Jennings is all too happy working with his friends. "They're people who would listen to my records whether I was with them or not," he said. "That's why I felt like I had the freedom to make a record I love and to turn it in as-is. I figured they'd be just as stoked as I was about it."

Johnson clearly was stoked. "I'll just be listening to his record around the house, and I feel lucky that I can call him up and tell him how much his music means to me, and to get to talk to him about it," he said.

Mason's right: Jack's fandom is a little weird, but cool nonetheless.