When Stevie Nicks and Lindsey Buckingham released Buckingham Nicks in 1973, they were just a couple of nobodies. Two hippie kids lost in L.A., doing an unfashionable folk-rock flower-child record.

It’s been a wild week of cryptic lyrics, mysterious billboards, and Mick Fleetwood reminiscing to “Frozen Love” on his headphones. But the wait is over: Lindsey Buckingham and Stevie Nicks will ...