The idea is to represent each note in 12-TET as a number, so N ∈ (0,1,2,3,4,5,6,7,8,9,X,Y).
I used codex to build a music score rendering backend based on MuseScore with custom note heads that display the pitch class of each note.
I've found it pretty helpful for learning how to play my own instrument, so wanted to share in case anyone else was interested.
It's not required that the pitch notation is absolute though, e.g. you can transpose the numeric notation to any key (e.g., use A == 0 instead of C ==0)
Basically it uses a regular pattern of keys, instead of staggering keys into pentatonic and diatonic scales, like a piano does.
This makes it harder to "find" the diatonic scales, but easier to transpose between different keys.
You can see an example here: https://www.youtube.com/shorts/kMD1qXtDAdg
But traditional notation is more compact, and for music based around diatonic scales, implies information about the harmonic function of notes that could be useful for interpretation.
There's a web site you might be interested in with many examples of isomorphic notation at:
archonis•42m ago
jmole•19m ago