actually the notion that european music is "harmonically rich and rhythmically unsophisticated" is incorrect; it's relatively modern phenomenon that the rhythms in european music were simplified. Traditional eastern european rhythms are incredibly complex and western european liturgical and vernacular music tended to have complex ryhthms until around the 16-17th century.
IIRC this was basically an effect of the church decided to try to monopolize music in the service of liturgy and "dumb down" the music so that everyone could participate in hymnals, etc.
This could also partially be a result of music printing; it's harder to notate complex rhythms - if you've ever sung medieval music that's pushed into modern notation, sometimes wierd things happen, like time signatures that don't quite line up with the all of the music lines because polyphony is going on; invasions of 3/4 measures in an otherwise 2/4 song, etc.
This sounds like how the early digital age of computers over-simplified analog processing of audio and video and PDEs (and what other complex phenomenon? Language AI?), and only later started to close the gap.
IIRC this was basically an effect of the church decided to try to monopolize music in the service of liturgy and "dumb down" the music so that everyone could participate in hymnals, etc.
This could also partially be a result of music printing; it's harder to notate complex rhythms - if you've ever sung medieval music that's pushed into modern notation, sometimes wierd things happen, like time signatures that don't quite line up with the all of the music lines because polyphony is going on; invasions of 3/4 measures in an otherwise 2/4 song, etc.