That's right. DNF. The damned Bible did me in. Had I known Jacob's father-in-law, I wouldn't have needed to know ATTLEE (41A: British P.M. after Churchill) or BARA (45A: Theda of the silents) (??), but as I knew neither of those two for sure, and I certainly didn't know LABAN, it was a DNF through and through. I also didn't know EPPS (1A: "House" actor Omar), but that was irrelevant.
Enjoyed seeing VONNEGUT (39D: "Slaughterhouse-Five" novelist) in the grid, and the "rotating" theme was pretty sweet. All the theme answers were solid. I also liked the clue for CANINE (32A: Dog or dogtooth), but ELHI (16A: Grades 1-12) reared its ugly head again, and I don't really think of a CHORD as being 12D: Part of a guitar riff. Riffs, to me, are more of a single melodic line. I suppose a chord could be thrown in every once in a while... still, not my favorite.
Other than that, not much to say.
p.s. Rex Parker and we are often, I think, on the same page with puzzles, but not today. He rated this one "Easiest Monday of All Time." Welp... not for everyone.