Sometimes a scene set in a given time period will have music in the style of that time period as BGM. This isn't about those cases.
This is for when, whether out of misunderstanding of what a time period's music style was, or deliberately, (for whatever reason) the scene is set to a style of music from a different era than the scene is set in.
- The 2013 CBC movie Jack, about Canadian politician Jack Layton, starts out with a scene of Jack Layton in his old age joggigng down a Toronto street with the 80s Parachute Club song "Rise Up" playing in the background... but immediately afterwards it's implied to be from within months of the 2011 election.
- All of Baz Lurhmann's movies use music from the wrong era.
- A Knight's Tale took place in medieval times yet the crowd did the stomp stomp clap riff from Queen's "We Will Rock You".
- Averted in Iron Man 3; it started with "Blue (Da ba Dee)" from 1999, but that's because it turned out to be a flashback a few seconds later.
- Played deliberately in Bioshock Infinite which mixes period hymns and other pieces with anachronistic tunes such as Tears For Fears' Everybody Wants to Rule the World and CCR's Fortunate Son in the game's 1912 setting. justified by people exploiting Elizabeth's powers to tear into alternate dimensions and covering the songs in the styles of their time period.
- Sofia Coppola's Marie Antoinette purposely uses 1980s music in a story about the 1700s.
- The film Moulin Rouge! uses contemporary music from the 1950s onwards to tell a tale set in 1899.