Most browsers can happily play a middle C or F# by referencing a MIDI file, or an audio file, or loading a simple ABC player (which is about as “text” a music representation as one could hope for, and which is limited thereby) or other app.
There are lots of existing solutions to music markup. Many are PD and/or opensource, and are already in use. The fact that you’re reinventing that basic layer, without justifying what your solution does that the others (with or without expansion and/or plugins and/or whatever) can’t, is not reassuring.
What you’re describing as desirable is tooling, not a new notation or new content.
