Convert midi to freq

$$ N_{Hz} = A_{STD} \cdot 2 ^ {N_{midi} - 69 \over \text{note_count}} $$

• $A_{STD}$ = default frequency

• https://en.wikipedia.org/wiki/12_equal_temperament

• https://en.wikipedia.org/wiki/Just_intonation

• midi control messages - for standalone - maps knobs to synth stuff

OSC

• https://ccrma.stanford.edu/~jos/DigitizingNewton/Example_Leaky_Integrator.html
• yt the audio programmer