It's a movie centered around a glass (h)armonica. It's live action, and there was something about magic. I remember sort of stained-glass looking sets, and that the (h)armonica was under attack and the main character was protecting it.
It is not "The Glass Harmonica" ('68), but perhaps a remake or something.
I saw it On Demand from Comcast under "free movies", about 8 years ago. I'm about 95% sure it was a full length movie rather than a short or a mere musical performance.
Can you help me identify it? They referred to the instrument as either an "armonica" or "harmonica", and it looked like this in the film but glowing and magical and stuff: