Audio problem: During "We Go Together" at the end, John Travolta's mouth is not in sync with the words "we'll always be like one." He appears to start singing "that's the way it should be" before realizing and correcting his mistake.
Audio problem: At the cotton candy stand at the graduation carnival, Blanche is seen silently mouthing the question "How many?" In the next scene, from a different camera angle, the same question is asked - this time with audio intact.
Audio problem: When Johnny Casino & the Gamblers perform "Hound Dog" at the National Dance Off, you can hear the song, but if you look carefully you can see it does not match the lead singer's lips.
Audio problem: When Sonny says "Shut up!" to Putzie outside Kenickie's car, his mouth doesn't move.
Audio problem: At the very beginning when they are singing "Summer Loving" Sandy sat at the top of the seating for the athletics track. The voice-over and Sandy's lip movements do not match.
Answer: It is implied that Danny and Rizzo had a previous romantic relationship of some kind. When Jan says, "Did you guys get a look at Zuk this Morning? Looking pretty good this year, huh, Rizz?" Rizzo replies, "that's ancient history." Later, when Danny says, "you're looking good, Rizz, " her answer, "eat your heart out," also suggests some possible residual feelings on her part. I think that's why Rizzo enjoys tormenting Sandy and Danny by reintroducing them at Rydell at a moment that she knows Danny is going to save face around his friends.
Michael Albert