There was a thread about odd musical instruments a few days ago, but I didn’t find a video like this one demonstrating some of the holographic pianos in development until today. The thread is closed now. The piano playing starts at 1:04:
But, to be honest, I was going to share this link to a holographic piano by Intel that is mentioned but not demonstrated. However, I thought, why steal Intel’s thunder? Why not just wait for them to announce it? Now, though, the K3 smart glasses thing above is near the top of smart glasses news on Google.