"__ the Roof"; 1962 song

I believe the answer is:

upon

(Other definitions for upon that I've seen before include "voucher, business stopped" , "Lying on top of" , "Immediately after" , "Thereafter" , "Atop" .)

I've seen this clue in The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.