Musical systems

When I was learning about music I took what my teachers taught me as the only possible way of conceiving of music. Maybe this is normal–baselines of knowledge are sort of unknown unknowns until interrogated. But perhaps the most mind-blowing musical concept I have ever discovered is outlined by Nick Baragwanath in this video, which I highly recommend: https://www.youtube.com/watch?v=xIpoeoqlvCM&t=3622s