"Play it, Sam. Play 'As Time Goes By"

Hi ppl,
What does the famous quote "Play it, Sam. Play 'As Time Goes By" mean?In waht context people use this?

Thanx
SS

I don't think people use it in any manner. They are just saying a quote from a movie. I could be wrong. I'll see if I can find it in a reference.

Sam isn't suppose to play the song because it reminds Rick of his lost love Ilsa. But after she shows up in Rick's bar and requests the song, later that night Rick tells Sam to play it for him. www.imdb.com/ title/tt0034583/