The plot reminds me of Otherworld from 1985 - Missing the comments section

Rating: 6/10 (14 June 2019)

Otherworld is an American science fiction series that aired for eight episodes from January 26 to March 16, 1985 on CBS. It was created by Roderick Taylor as a sort of Lost in Space on Earth. Taylor gave himself a cameo role in each episode. The series was later shown in reruns on the Sci Fi Channel.
In episode 4 the kids start playing and singing Beatles songs to this alternate universe crowd who have never heard them before.