1981: Pink Floyd’s “Dark Side of the Moon” breaks the record (pun intended) for most consecutive weeks on Billboards Top 200 Album Chart, notching its 491st week in a row. It would gone on (and on) from there, finally setting the record (still unmatched) at 741 weeks, leaving the charts (only to return shortly thereafter) in 1988.
The previous record holder? “Johnny Mathis’ Greatest Hits,” which took the title from “My Fair Lady” with the original Broadway cast.