Broadcast by NBC:
https://www.filmaffinity.com/us/film529189.html
Maybe someone at NBC could help?
Nominated for a Golden Globe award in the category for Best TV Special:
https://wolfememorial.com/2016/06/genius-the-movie/
An IMDB comment suggests that it hasn't been converted to DVD, so it might not be commercially available in digital format.
These look like high school performances:
https://www.youtube.com/watch?v=fOkGfVuYUV4
https://www.youtube.com/watch?v=YAE_0b-shMs
If you have a local film archive society, perhaps through a university or library, they might be able to help.
I wonder if someone in these subreddits would have a good lead: