[jgibson]

> dictates how to start a note (lacking the English term here)

Intonation perhaps? I often used the word "attack" to indicate the style of start of the note when I used to play flute, but I'd say thats far from proper terminology

[escherplex]

Try embouchure - https://en.wikipedia.org/wiki/Embouchure

[shhsshs]

I think articulation would be the word here

[escherplex]

True. embouchure is more mechanics. If you wanted to sound pedantic you probably could use the Italian accentuazione :-)