[duped]

I think a trend in contemporary theory is the understanding that western music study is a like a philosophy for how it's been taught and understood for a few centuries. There are a lot of composers that have outright rejected the practice to bring in influences and learn from other cultures in the last half of the 20th century, and more recently schools will teach students some pedagogy from other cultures or perform works from non-western composers as a means of exposure.

The kind of downside is that until the late 20th century, music education (including theory) was basically a master/apprentice relationship and even today we have a lot of that tradition baked into the formal study.