In late August of 2019, Australian Christian duo For King & Country enlisted country icon Dolly Parton for a remix of their song "God Only Knows." It was a match made in heaven: Brothers Joel and Luke Smallbone were eager to collaborate with Parton after seeing her Netflix film Dumplin', and Parton was looking for more faith-based material.

Even before Parton got involved, "God Only Knows" was a hit, though: The original version of the song hit No. 2 on the Billboard Hot Christian Songs chart, logging a record 19 weeks in that spot and staying on the chart for 60 weeks in total; it also spent 10 weeks at No. 1 on the Christian Airplay chart. And, once Parton got involved, the song cracked the Billboard Hot 100 (No. 94) -- a first for For King & Country.

Parton isn't the song's only Nashville tie, either: For King & Country co-wrote "God Only Knows" with Music City-based writers Josh Kerr, Jordan Reynolds and Tedd Tjornhom. Below, Kerr shares the story behind the song, and his time in the studio with Parton.

It's funny, for how often I write country that, you know, then I go in with the Christian guys. 'Cause I really just wanted to write with For King & Country; that's what I wanted to do so bad. And so I went in -- and I was raised on Christian music -- so I just actually felt like, you know, at this time in my life, I needed to be writing some Christian music. That's kind of how I was raised, and so I went in with them and we ended up writing "God Only Knows" ...

Writing the song was -- it was amazing. We all went in and we all had no idea the struggles that -- We all had different stuff going on in our lives that the other people maybe didn't know about, which is the most ironic part about writing that song, 'cause, literally, it's "God only knows what you've been through and what you're going through," and we were all going through different things without knowing it, writing this song.

And it just became something that we -- We honestly didn't even know what it was gonna be, and it kept evolving, and we got to put Dolly Parton on it, and it's amazing to be part of that. Oh, yeah, it was insane [to work with Parton on the song]. I showed up [for her recording session] three hours early; I was like, "There's no way I'm gonna be late," so I sat in my car for a long time, just, like, in case of some freak accident or something ...

I walked in, and within five minutes of meeting her, she's like, "Alright, I need you to sing this song with me. Like, right now."

And I was like, "Just us?" And there were guitars around, so I was kind of reaching for a guitar. And she goes, "No, no, just me and you, a cappella."

I was like, "Oh ... kay." So I just sang with Dolly Parton within five minutes of meeting her. But she's such a pro; she would have sang it a million times if she needed to. She'll just sing it 'til it's right ... It was amazing. She's the sweetest, sweetest woman on the entire planet.

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