Stevie Nicks performed Fleetwood Mac's 1975 hit 'Rhiannon,' and even gave a few lessons in shawl twirling, as a guest star on last night's episode of 'American Horror Story: Coven.'

The series focuses on a Louisiana-based witch named Misty Day (played by Lily Rabes) who may be Nicks' biggest fan -- she even sports a 'Bella Donna'-era wardrobe. Could an appearance by Nicks herself been too far behind for the FX TV show?

Nicks, however, said she needed some convincing: "When they called and asked me if they could use my music, they just explained it a little bit: There’s a character, and you’re a muse because she listens only to you — and she lives out in the swamp. And that was good enough for me! I’m like, 'Sure, you can!'"

Turns out that during filming on the set in New Orleans, Nicks learned that Rabes is actually a huge fan in real life too. That led to some starstuck moments.

"She did faint about 700 times when we were doing that one scene!" recalled Nicks. "I was afraid she was going to have to go the hospital. She’s really a lovely girl, and she does love my music. Every time I’d play a specific song, she would start to cry. I would say to her, 'You know, you don’t really have to cry.' And she said, 'No, no -- that’s not acting.' So I said, 'Well, then that’s OK, you go right on ahead and cry.'"

'Rhiannon,' which just missed the Top 10 in 1976, was Nicks' breakthrough song with Fleetwood Mac. It's long been rumored to be about a Welsh witch.