Stevie Nicks Reveals a 'Horrible Wrench' Was Thrown into Her 1983 SNL Set. How Her Sister-in-Law Saved the Day (Exclusive)

• Stevie Nicks will be the musical guest on Saturday Night Live on Oct. 12
• The performance comes two weeks after she released her new song "The Lighthouse"
• When she first performed in 1983, Nicks' sister-in-law Lori joined her to sing backup last-minute

Before Stevie Nicks returns to Studio 8H to perform for the first time in 41 years, she's looking back on her first Saturday Night Live performance.

The rock legend — who recently released her new pro-choice single "The Lighthouse" — will take the stage as SNL's musical guest on Saturday, Oct. 12, alongside host Ariana Grande, marking the Fleetwood Mac singer's first performance on the show since 1983.

"That was about 2^1/2 years into my solo career, so it was nerve-wracking because it was not Fleetwood Mac; it was my solo career, so it was very scary to go on the show when you've been in a huge band and now you're going on Saturday Night Live as a solo artist," Nicks, 76, tells PEOPLE exclusively in an email interview.

In December of 1983, Nicks performed two tracks from her sophomore solo album: "Stand Back" and "Night Bird."

"You know, we practiced and practiced, and everything went well. At the time, I had my friend who wrote 'Stand Back,' and she was gonna do the second song, which was called 'Nightbird' — and she freaked out and had terrible stage fright, so she couldn't do it," Nicks says.

Instead, Nicks found a last-minute replacement.

"So one of my singers, who ended up being my sister-in-law Lori, she said, 'I'll do it,' and she's crazy, but she said, 'I'll do it,’ " Nicks says of her longtime backup singer Lori Perry. "This is literally right before we went on, and so we went on and we did it, and it came out perfect!"

Despite the impromptu lineup change, "It was one of those shows, that even with that horrible wrench that was thrown in the middle of it, it came off beautifully," Nicks adds. "I've never been so proud of anything as I was of that night. It was a magical show, and I was thrilled, and it definitely kicked my solo career up."

Now, more than four decades later, Nicks still has nerves, despite her iconic status.

"Well, performing on Saturday Night Live is now as it was then. It’s just about the biggest thing you can do, bigger than a stadium show because it's going to go out all over the world," she says. "So if you wanna talk about being nervous about something! It doesn't matter how many shows you've done or how much you practice, you're going to be nervous!"

Adds Nicks: "You can never say that Saturday Night Live does not help you to gain lots of new followers, younger people, older people, etc. And so to be asked to do it again ... I never thought I would do it again — so to be asked to do it again has thrown me into an absolute nervous frenzy, but I'm really excited. I'm really excited to play the new song."

When she returns to SNL, Nicks is expected to play her new song "The Lighthouse," which she wrote as a call to action after the Supreme Court overturned Roe v. Wade in 2022, eliminating the constitutional right to abortion.

“I find it very sad, at 76 years old, I had to see Roe v. Wade taken away," Nicks recently told PEOPLE exclusively. "Two years ago, when I realized the consequences of women’s rights that are vanishing, I watched a lot of news, and I was like a sponge — it just went into me.”

Women's reproductive rights are a personal subject for Nicks, who in 2020 revealed to The Guardian that she "would have had to walk away" from Fleetwood Mac if she hadn't gotten an abortion in 1979. Without the procedure, "I’m pretty sure there would have been no Fleetwood Mac," she added at the time.

“All the stories that we tell about the necessity for women's healthcare and the necessity for a safe and legal abortion option for women is absolutely necessary," she recently told PEOPLE.