I think a musical language should be able to be singed. That leaves chords out of the question. Also weird intervals.
Some brainstorming. We have:
Musical elements easy to sing:
-We leave out absolute pitches.
-Note length: short/long
-Note articulation: legato/stacatto
-Pitch movement: Up step, down step, up skip, down skip, repetition
How to transcribe our consonants and vowels:
We use a short onset. Then, using pitch movement and articulation:
Stacatto: Ka (up step), pa (up skip), ta (down step), ja (down skip)
Legato: La (up step), ma (up skip), na (down step), sa (down skip)
No ornament: A
upper step ornament: E
upper skip ornament: I
lower step ornament: O
lower skip ornament: U
Long note: start of word / accent
mi wile moku. moku li pona.
Transcribed into a simple Lydian fifth-range
just playing with the idea. Nothing serious about it.