Stevie Nicks wowed the audience with a surprise performance of 'Rhiannon' after the young cast of 'School of Rock' took its curtain call at Broadway's Winter Garden Theater.

Nicks saw the show on opening night, then returned Tuesday (4/26) to see it again and perform with the young musicians.

“I have Fleetwood Mac, and then I have my solo band that I’ve been playing with since 1980, and now I have one more fantastic band to add to my roster, so I’m very happy,” Nicks said backstage.

Nicks tells Page Six that she enjoyed performing with the School of Rock cast, because it helps raise money for Broadway Cares/Equity Fights Aids. The organization provides financial support for people with AIDS, HIV and HIV-related diseases.