Cruel Summer by Bananarama was played on the first day of school in The Karate Kid as well.
Mary Mouser injured her hand and missed almost an entire day of filming, meaning the entire filming schedule had to be rearranged so that all of the sequences not involving Sam could be filmed in her absence and everything she was needed for would instead be filmed the following day. Mary initially wanted to fight through the pain and continue shooting, only for one of the directors to insist on giving her the rest of the day off so that she could go to the hospital and get it treated properly, even though this meant the entire cast and crew would have to adjust at the last minute and film huge chunks of the fight with limited preparation.