Is like saying "Synthesizing Music from a binary file" if you write a S3M player.
Outside of that, congrats. I think the author has enough "fame credits" to make any project an instant success. Kudos for that.
This is just using JSON as an encoding format. (And as a "legacy" one, too, it seems like its moved to JS.)
> it becomes easy to imagine using existing JSON based tools to create music.
No … it really doesn't? I am trained in both music and JSON, and I have no idea how that'd work.
Because you don't have "something that 'plays sound' from JSON" you have something that plays sound from application/sonant-x+json ; the interesting bits are in the "application/sonant-x" but your tooling only understands the "+json".