Fans are abuzz after Stevie Nicks and Lindsey Buckingham, the former Fleetwood Mac bandmates who were once romantically involved, posted lyrics from “Frozen Love.” Days later, a billboard popped up in Los Angeles teasing a new project and fueling rumors of a possible reunion.

Stevie Nicks and Lindsey Buckingham have sparked reunion rumors with seemingly coordinated Instagram posts. The musicians famously dated in the late ’60s and made the 1973 studio album “Buckingham Nicks.” Shortly after, Nicks, 77, and Buckingham, 75, joined Fleetwood Mac.

The 1973 album was a commercial disappointment upon release, but has enjoyed a cult legacy ever since, in part thanks to its elusiveness: Buckingham Nicks never received a remaster or reissue after its debut, and thus became largely unavailable for decades. On September 19, that will finally change.