When you have two talented people with guitars together for any length of time, a song will probably emerge. Such is the case with Blake Shelton and Miranda Lambert, who have started to write together.

"That's another part of our relationship that's grown," Shelton tells The Boot. "You know when you have two people who are country music artists that write songs and love to sing, and you're sitting around a campfire at midnight, sooner or later a guitar is going to appear. Next thing you know we were writing a song."

Not only a song, but as he describes it, "some of the coolest music that I've written has been with Miranda." Songwriters bare their souls to each other during a writing session, so it makes sense that for a couple who already know each other very well, the writing would come pretty easy for them. Plus, Lambert already has experience picking songs for Shelton, since she was the first person to play his most recent No. 1 song, 'Home,' for him.

Despite the fact that the couple's music is miles apart -- she is rather edgy and he is more traditional country -- Shelton explains that it makes for interesting songwriting sessions. "You can do some things that are new with an artist like Miranda. She breaks the mold. She can pretty much get away with anything, and as a writer it's exciting for me to be able to explore that and go there with her."

Shelton has already picked one of the songs they wrote together to go on his next album. It's a stripped-down song that came out of an intimate recording session, appropriately titled 'Bare Skin.'

"What's cool about it is we just recorded it sitting around the campfire and that's all it is -- me playing guitar and her singing with me. There are no other instruments, and there was no studio involved. I'm real excited for people to hear that because that is Miranda and I. When people say 'What do you all do,' well, when you hear this recording that's what we do when we're home. We drink a few beers and sit around the campfire and play our guitars at night."

Shelton says Lambert has promised to put a song or two they've written on her next album, as well. He says with a laugh, "I'm going to kill her if she doesn't, but we'll see." The couple's farms are becoming a haven for Nashville songwriters. Charles Kelley and Dave Haywood from Lady Antebellum flew out to his Oklahoma house recently to write.

"They stayed with us for two days and we just sat around and wrote songs," Shelton recants. " No record companies involved, no publishers, no concerts -- just the four of us sitting around. We wrote I don't know how many songs, probably five or six. When you get away you're able to you have so much freedom than when you're sitting in a room in Nashville trying to write a song. You're sitting somewhere writing a song because you feel like it. It's pretty cool."

Shelton and Lambert embark on their first joint tour together this fall. It starts October 3 at the Virginia State Fair in Richmond, with shows booked through November 8 in Dallas.