The veteran entertainer first met Perry in London in 2011, when they were both in town for separate performances, and what Nicks expected to be a 20 minute chat session turned into a three hour sit-down, during which they discussed every topic imaginable.
And in an interview with ABC News Radio, Nicks recalls that the most fascinating point of the evening came when Perry started quizzing the veteran about her solo career, which took off in 1981 with the release of her debut album, Bella Donna.
Nicks says, "She said to me, 'So when you did Bella Donna who were your rivals?' And I was, like, speechless. I was, like, 'I didn't have any rivals.' And she said, 'Really? None?' I said, 'No... the girls in Heart were friends. Pat Benatar was a friend'."
Turning the tables on the Teenage Dream singer, Nicks then asked Perry if she had rivals and she replied, "Well, it’s not us. It’s the Internet", referring to the passionate fans who are quick to start up feuds between their favourite artists.
Eager to give the 29 year old some advice, Nicks recalls, "I said to her, 'Katy, let me tell you something. You don’t have any rivals. So forget that. Never say that word again. You don't have rivals. All of those girls? Friends. You'll probably work with all of them at some point. Friends.'"
Nicks recently surprised Perry at a Fleetwood Mac concert in Las Vegas on 30 December (13), when she dedicated her hit song Landslide to the singer and her beau John Mayer, who were in the audience.