Kacey Musgraves is climbing up the charts with her latest hit, "Biscuits," the debut single from her upcoming, still-untitled sophomore record -- but the inspiration for the song dates back to before her first album even hit the shelves.

"One day, we were out, somewhere outside of Nashville," Musgraves recalled during a surprise appearance at Tin Pan South 2015, during Shane McAnallyBrandy Clark and Josh Osborne's round. "It was last July. It was me, Shane, Josh, Brandy and Luke Laird. We all traded off writing with different [people] ... we'd draw names out of a hat."

McAnally, Clark and Musgraves are the three credited songwriters on "Biscuits;" they're also the same trio that wrote Musgraves' award-winning single, "Follow Your Arrow."

"Here's what happened: We had started this song when we wrote "Follow Your Arrow,"" McAnally interjected. "'[Mind your own biscuits]' was something we had said in another songwriting thing, and you brought it."

"We were like, 'That has to be a song, the whole idea,' and so we saved it," Musgraves continued. "I feel like it was Brandy, because she's like, if there's a puzzle piece missing in a song, she's just, like, infamous for [saying], 'You know, this may not work, but what about this?' And it always works. It's mind blowing. You're like, 'Oh, you just pulled this out of your little pocket there?'

"[McAnally] said, 'Mind your own biscuits,' and [Clark] said, 'And life will be gravy,'" Musgraves added. "And I was like, 'I quit. Bye. Brandy, get out. You're too good.'

"So a lot of people ask about the inspiration behind it," Musgraves concluded, "and all I have to say is, it's just good ol' plum country fun."

Although she didn't share many other details about her upcoming project, which will reportedly be released in June, Musgraves did reveal that McAnally, Clark and Osborne all have cuts on the new record.

"I love these three people here," Musgraves said of the trio of songwriters on stage with her. "Without them I probably a) would never laugh, and b) would never have any songs. We actually just finished a record, pretty much yesterday. I'm really excited. I'm really pumped."

Download "Biscuits" on iTunes.

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