Not long ago, Sting challenged his friend Paul Simon to write a song with him. "The next question is, what do we write about?" Sting says mischievously, taking a break in a Manhattan recording studio. "We're not going to write about getting laid. Or cars. So I don't know."
In the meantime, the two singers have another project to work out: their first-ever co-headlining tour, which kicks off February 8th in Houston. Though they've been pals since the late Eighties, when they became neighbors in a New York apartment building, Sting and Simon had never performed as a duo before last May, when they played acoustic versions of "The Boxer" and "Fields of Gold" at the annual Robin Hood Foundation benefit. "I wasn't sure how it would sound," Simon says. "But after we got offstage, we said to each other, 'That was actually pretty good.'" Adds Sting, "There was this audible gasp in the room. We thought, 'Why don't we see if we can take it somewhere else?'"
Each night of the tour will feature multiple duets by the two artists, along with solo sets. Simon says he'd love to sing Sting's "Fragile," and Sting may do Simon's "The Boy in the Bubble." They're also considering connecting songs thematically: Simon told Sting he wants to attempt "Brand New Day," which Sting thinks would pair nicely with "50 Ways to Leave Your Lover." "It's a song about a beginning and a song about leaving," Sting says. "We can find little contrasts in the set." Simon has also asked Sting to tackle "Bridge Over Troubled Water." "Not that I want to imitate Art Garfunkel," Sting says. "He has one of the most beautiful voices in the history of pop. But I can hit those notes. And," he adds with a smile, "it might have more resonance now with Chris Christie."
Both men have other projects under way: Simon is working on a new studio album, and Sting is planning for the June opening in Chicago of his musical The Last Ship, which will hit Broadway in the fall. But both say the collaborative-tour idea was too good to pass up. "It's really about exploring new possibilities," says Simon. "We've both worked with reggae. This has the potential to be something special."
Adds Sting, "I've always liked good music – I might have looked like a punk in the Seventies, but I wasn't one. Paul's intention is always to get better. That's one of my obsessions, too."
This story is from the February 13th, 2014 issue of Rolling Stone.