MacArthur Park was the longest running 45 RPM record I ever saw, clocking in at something like 7:45 or so. The grooves were visibly smaller than other records. Breathe on the tone-arm and it would skip.
"MacArthur Park" was the first single hit to run past seven minutes in 1968, right before the Beatles' "Hey Jude." Then, in 1972, came the surprise of the year: Derek & the Dominos's "Layla" issued full-length on a single . . . two years after their only tour and their breakup while trying to record a second album. (The song was included on a two-LP anthology,
History of Eric Clapton, in spring 1972 and---after an edited version bombed as a single in early 1971---hit the top ten nationwide and number one in several markets.)
A year earlier, jazzman Cannonball Adderley had a composition by his brother, Nat, "Games," on the B-side of a single and clocking in at 7:00 even. Since it was the B-side, of course, it got little to no airplay and didn't get anywhere close to what was on its plug side: "Mercy, Mercy, Mercy" . . .