There is plenty of music theory not based on traditional western music.

The "atom" of all music is that frequencies with simple relationships (for example, exactly 1/3x) sounds "nice" (we can hear the harmony) and frequencies with complicated relationships (pi x) sounds sour (used intentionaly with great effect by bands like Sonic Youth for example).

The essence of western music is the decision to split the octave into 12 and have this be the notes we use (anyone who have tried this will discover that we run into trouble when our instument tonal range spans more than one octave, this is where "tunings" come in).

But there are alternatives: Spliting the octave into 53 parts has way more harmonies

https://en.m.wikipedia.org/wiki/53_equal_temperament

This is partialy used in turkish music for example.