By Nick Romano
July 16, 2018 at 12:00 PM EDT

The moment Dolly Parton felt she had “arrived as a writer” was the moment she heard Whitney Houston‘s “I Will Always Love You” over the car radio. The country legend called up the memory in a sit-down with fellow southern belle Reese Witherspoon for the new Shine On With Reese interview series, and EW has the first exclusive clip of that conversation.

“She took [the song] to so many levels,” Parton said. “To think that my little song — my little heartfelt, heartbreaking song — could be that big, I felt that I had arrived as a writer.”

Parton wrote and recorded the original “I Will Always Love You” in 1973, and the song was then released as part of her Jolene album a year later. The song was written as a farewell to Porter Wagoner, Parton’s partner for the previous seven years whom she was leaving to pursue a solo career.

As Parton explained to Witherspoon, Kevin Costner reached out to the singer-songwriter to see if “I Will Always Love You” could be used in his 1992 film The Bodyguard, which starred Houston as a pop singer protected by a former Secret Service member (Costner).

“I sent it out, totally forgot about it,” Parton said, “and then I was driving home and all of a sudden I hear this sound on the radio.” She remembers thinking her “heart was gonna bust” the moment Houston’s a cappella opening came on. “I had to pull over lest I should wreck,” Parton added. “It was the most overwhelming feeling I’ve ever had.”

Witherspoon will interview other “extraordinary women” like her A Wrinkle in Time director Ava DuVernay, Pink, America Ferrera, and Kacey Musgraves for Shine On With Reese. The series, a joint effort between her media brand Hello Sunshine and AT&T, will explore “what inspires, motivates, and gives joy to each of these trailblazers” and hears “their perspectives on ambition, work, family, and hopes for the future.”

Shine On With Reese will premiere July 17 on the Hello Sunshine Video on Demand channel for DirecTV, DirecTV Now, and U-Verse.