Katy Perry and Kacey Musgraves became fast friends after discovering their mutual admiration for each other. The two singers will hit the road for a month while Musgraves serves as the opening act for Katy Perry's Prismatic Tour, and they recently performed together for a taping of 'CMT Crossroads.'

But that's not all that they have in common. It turns out they are both big fans of the classic film, 'The Wizard of Oz,' which served as the inspiration for a song they collaborated on together for their 'Crossroads' taping.

"I brought some ideas, and we actually ended up writing a pretty cool song," Musgraves reveals to Billboard. "It's loosely based on Dorothy's version of 'The Wizard of Oz,' her being in love with the Tin Man, but he didn't have a heart. And hopefully maybe something will happen with it down the road. Either way, it's cool to step out of my zone and write for somebody else."

Musgraves' run with Perry kicked off Sunday night (Aug. 10) and will last for a month.

"It's going to be really interesting and really good for me, I believe, 'cause there are a lot of people who would probably never have heard country music otherwise," the 25-year-old states. "So I'm proud to be an ambassador, and if I pick up some new fans along the way, I think that's great. I think with Katy, with her music and style, anything goes, and I think if people are just coming to hear great music and have a great time, it'll make sense."

The 'CMT Crossroads' episode of Musgraves and Perry first aired in June. Watch the entire episode here, and see a list of all of their upcoming shows here.