. ♪ ♪ we go together like ram ma la ma la ma ♪ >>> can you imagine anybody else playing danny and sandyvolta and olivia newton-john? say, for instance, henry winkler and marie osmond? it could have happened. we're getting the the party started early on this flashback friday. ♪ you're the one that i want you are the one that i want ♪ >> can you believe it's been 40 years? >> i can't. can you? no, you probably weren't born yet. you weren't born yet. >> i loved that movie growing up. >> sandy! >> danny! ♪ working up the quarter mile >> who was the first actor considered for the role of danny zuko? >> ay! >> john said a olivia wasn't the first choice either. >> they brought up linda ronstadt. marie osmond. i said, they're wonderful. but every -- every guy in the world wants olivia newton-john as their girlfriend. >> oh. ♪ summer days drifting away >> and i knew that because i wanted it. i felt the same way. okay. and every girl wants to be like her. and i said, if you don't see this, you guys are nuts. >> olivia was 29 at the time and was afraid she was too eold to play a high school studen