(CMT Offstage keeps a 24/7 watch on everything that's happening with country music artists behind the scenes and out of the spotlight.)

Country songwriter Mark Irwin was in Chicago on Thursday (Jan. 24), and I had a chance to ask him about the songs he co-wrote on Tim McGraw's upcoming Two Lanes of Freedom album. Irwin, who refers to himself as a "song maker-upper," talked about what a really good song picker McGraw is.

"That he thought these songs were good enough to be in the whole lexicon of songs he recorded is really exciting," Irwin said. "He's one of the few artists who hasn't started writing, himself, just to put his names on songs. He turns to writer to do their jobs. That's always worked for him and he's a really smart guy."

Irwin, who grew up going to open mic nights in and around New York City, decided to pack up and move to Nashville in the late '80s after people kept telling him he was "way too country." And now, more than two decades later, he's certainly country enough. After writing songs for Alan Jackson, Martina McBride, Jimmy Buffett, Hank Williams Jr. and many others, he's now on the verge of McGraw's album release. The album has three songs that Irwin co-wrote, including the much-anticipated duet with Taylor Swift, "Highway Don't Care."

"It was Tim who came up with the idea to put Taylor on it. It's basically about a guy leaving someone and driving around and trying to forget the person they're leaving," he said. "Then, of course, the song comes on the radio that reminds them of that person and makes them think about things even more." He described it as a mid-tempo kind of groove and very modern country. "It's just very Tim." Keith Urban has a guitar solo on the song, and when I asked Irwin about that, he said, "Tim really wanted to make this song an event."

Other songs Irwin helped pen include "Friend of a Friend" and "Tinted Windows." That one, he told me, is about first cars and first loves. "It's an old story about how through the years, things can change and how love can fade," Irwin said. "It's a metaphor for looking into his lover's eyes, and her eyes are tinted windows, so he's not sure what he sees behind them."