"I Will Always Love You," later popularized by Whitney Houston, is an iconic song in music history.
But contrary to popular belief, the lyrics center on the end of a professional relationship, rather than a romantic one.
In the late 1960s and early 1970s, Parton appeared with her mentor Porter Wagoner on his eponymous TV show. But when it came time for Parton to spearhead her own career, Wagoner was not happy, and a rift started forming.
"There was a lot of grief and heartache there, and he just wasn't listening to my reasoning for my going," Parton told CMT in 2011. "I thought, 'Well, why don't you do what you do best? Why don't you just write this song?'"
Parton penned "I Will Always Love You" later that day and sang it to him the next.
"He started crying," Parton told the Tennessean in 2015. "When I finished, he said, 'Well, hell! If you feel that strong about it, just go on — providing I get to produce that record because that's the best song you ever wrote.'"