It wasn’t an old song – the artist was pretty young.
There was a guy who was watching a ballet class and he came in after everyone else left and he started dancing. A dancer saw this and began teaching him.
And then there was a girl who was learning karate or mixed martial arts in a class. It shows the girl beating some guy up who attacked someone.
Fast forward to years later and the guy is putting on makeup and getting ready to perform. The girl is getting ready for a fight- at the Olympics, representing France.