While working on their third studio album, Interstate Gospel, country trio the Pistol Annies relied heavily on their magnetic songwriting connection -- but according to group member Ashley Monroe, the music may have also gotten a little help from beyond the grave.

"One-hundred percent, we hope that we bring all of our favorite songwriting ghosts around us to haunt us while we write," Monroe tells The Boot with a laugh. While they writing, Monroe, Miranda Lambert and Angaleena Presley were all listening to the Andrews Sisters, hoping the ghosts of the swing group known for their close vocal harmony might find a way to interject their sound into Interstate Gospel. Then, Lambert had the idea to add the Andrews-inspired ending to the album's first single, "Got My Name Changed Back."

"It was cool, because we had been telling the Andrew Sisters, the angels of 'em, to come onto our record," Monroe recalls. "We wanted to do an Andrews Sisters part. That was the last song we expected them to pop up on!"

The Annies have been visited in the writing room by the spirits of other favorite artists, too, Monroe says: "Guy Clark, I swear he haunted us a little bit while we were writing."

"[Angaleena Presley] was really close with him. Miranda was, too. I was. And it was like, I felt him," she insists.

Aside from inspiration, Clark's ghost also provided a little bit of friendly competition. "It was like we were trying to show off for him, songwriting-wise," she says, explaining that while the Annies' spiritual guides help push them to deliver the best work they can, one thing's for certain: The ghosts are friendly.

"We definitely have our angel heroes that we hope sneak in," Monroe adds.

Interstate Gospel is due out on Friday (Nov. 2).

5 Things We Learned About the Pistol Annies at Their Reunion Show