I may not be the target demographic for this, but a couple of things piqued my interest with Simply Piano for Apple Vision Pro.
Overlaying finger numbers on the fingers was a pretty neat idea and I can see this being helpful for beginners.
Performing in front of an audience! The guy demo'ing this said he had goose bumps playing in front of the simulated audience. For someone like me who has a debilitating case of stage fright, I can only imagine the possibilities here of practicing in front of a variety of friendly or hostile virtual audiences.
All in all, it's great to see new ideas in action!