I will never forget in "American Hustle" when the Christian Bale and Amy Adams characters are talking about their love for Duke Ellington, and they pull out a vinyl copy of "Ellington at Newport," and it's a cheesy reprocessed stereo re-issue, because that would have been contemporaneous for 1978 or whenever, and they listen to "Jeep's Blues."
Kevin Kline humming/singing the theme from "Raiders of the Lost Ark" in "The Big Chill" (a film directed by Lawrence Kasdan, who wrote the script to "Raiders") before going upstairs to fight the bats in the attic. Classic.