Indeed.'Theory' is probably not the best word
That word has evolved - in English - and wrapped itself in connotations so that it's use in non-sciences doesn't work or sets up expectations that are (no longer?) fulfilled. So people go "pha! Theory! That doesn't work in music!" - and quite right; not because music "theory" is no good but the meaning of theory has shifted
I'd'v thought Music Analysis would work, but, go on, what might be a better word?

. But I have a book called "Music Theory in Ethnomusicology" which pretty well has to! But "copy" is disabled... So here's a screenshot of that.
