Film class editing assignment (circa 2010s). Not perfect. Highly rudimentary editing skills. It's not exactly my own idea; the work is highly derivative from one of the videos I watched on youtube wayback in time, when youtube was about to sprung out to world around.
Late 70s was certainly a class apart. Thumbnails can be misleading, I know you weren't expecting this!
If you are looking for original dance sequence from movie, check this one out by frontera2032 - https://www.youtube.com/watch?v=fy0rYUvn7To

Disclaimer: I do not own the copyright.