AceShowbiz - Dolly Parton has comedian Jimmy Fallon to thank for kickstarting work on her new holiday album, because she always regretted turning down the opportunity to sing with the funnyman years ago.

The country music queen recruited the U.S. late night host to record a cover of Mariah Carey classic "All I Want for Christmas Is You" for "A Holly Dolly Christmas", and it was only after hitting the studio together that Parton decided to make it into a full duets project.

"I didn't think about doing a bunch of duets at the start," she confessed.

"When I was on ('The Tonight Show Starring Jimmy Fallon') a couple of years ago around the holiday season, he had asked me if I would sing with him, Mariah Carey's song... and I didn't know it good enough to sing it, and I didn't want to mess it up, so of course I said no... and it really bothered me."

After teaming up with Fallon, Parton called on pals including Willie Nelson, Billy Ray Cyrus, Michael Buble, and her goddaughter Miley Cyrus to get into the festive spirit with her.

"Then I got to thinking, 'Well, maybe I'll get all these other guys to sing with me'," she continued.

"It was just one of those perfect storms, where everything fell like it was supposed to."

Released in October, the song opens with Dolly aksing Jimmy, "Hey, Jimmy. I don't know how to say this without sounding all mushy and romantic." Later, Jimmy is heard replying, "I kinda like mushy and romantic." She then responds, "You do?" she responds, to which he says, "Yeah, especially this time of year."