'American Horror Story: Coven's' Stevie Nicks: The Supreme is a mystery to everyone

lily-rabe-stevie-nicks-american-horror-story-coven.jpgLegendary songstress Stevie Nicks is lending not only her dulcet tones but her acting chops to "American Horror Story: Coven" starting Wednesday (Jan. 8). She tells E! Online that when she signed on to guest star, she envisioned herself simply walking through the set and perhaps saying hello to the witches. But that was not the case.

"I get to New Orleans and in New Orleans, I get this script and it is not just me walking through," says Nicks. "My assistant reads it out loud to me at 3 in the morning and I'm pretty horrified because I'm going, 'Do they know that I'm not an actress? Has anybody told them that I've never, ever done anything like this in my whole life?'"

But never fear, fans. We can tell you she does a lovely job. In fact, she was so great that creator Ryan Murphy expanded her guest-starring role from one episode to two. Plus, in her debut episode, titled "The Magical Delights of Stevie Nicks," fans are in for not one but two performances by the Grammy-winning artist: "Rhiannon" and "Has Anyone Ever Written Anything for You."

"They chose them because 'Rhiannon' was Misty's anthem and 'Has Anyone Ever Written Anything for You' can work for anyone in the world when they've had a very long, bad day," says Nicks.

"It was really a beautiful thing; it was like a dream," she continues. "Everybody just moved slowly. I figured that those times will never come again. When I'm 90 years old and I look back over my life, I'll remember Jessica Lange leaning over the piano and saying, 'That was a difficult day,' and walking over to the couch. I'll never forget it."

As for the on-going plotline of which young witch is the new Supreme, Nicks says that she isn't telling -- because she doesn't have anything to tell.

"I'm telling you, as god as my witness, nobody on that set knows. Nobody but the writers know, and the writers weren't even there," says Nicks. "So, I've gone through every idea I could get to. ... I'm going to be as surprised as everybody, because, believe me, they're not telling any of the actors."

"American Horror Story: Coven" airs Wednesday nights at 10 p.m. ET/PT on FX.
Photo/Video credit: FX