... is not an album by Led Zeppelin
. Led Zeppelin's fourth album
is officially untitled
, with the only markings on it being the four runes
that each member
of Led Zeppelin chose for themselves. They chose this course of action because they wanted their music to sell albums, not the name Led Zeppelin.
The album continues to be called four only because (1) it's their fourth album, and (2) because their first three albums were titled Led Zeppelin, Led Zeppelin II, and Led Zeppelin III. But it's not Led Zeppelin IV. It doesn't have a title.