Ethnomusicology and historical musicology are primarily concerned with specific manifestations of music such as performances, works, traditions, genres, and the people who produce and engage with them (musicians, composers, social groups).
Its contents and methods are more diverse and tend to be more closely related to parent disciplines, both academic and practical, outside of musicology.
The origins of systematic musicology in Europe can be traced to ancient Greece; philosophers such as Pythagoras, Aristotle, Plato and Aristoxenus asked general questions about music.
Historical musicology and ethnomusicology are much younger disciplines, and the relative importance of the three has fluctuated considerably during the past few centuries.
Today, musicology's three broad subdisciplines are of approximately equal size in terms of the volume of research activity.