European classical music is great - when you ignore about a thousand years of religious singsang. Literally for centuries composers were obliged to repeat the same topics over and over again: kyrie eleison (Greek for ‘Lord have mercy’) etc.
Musical freedom and the development of more complex music came AFTER the catholic church had lost it’s stranglehold on ‘popular culture of the middle ages’. Actually the protestant revolution actually helped a lot to trigger that change.
Today when we hear real and fake Gregorian Monks chant it - it sooths our hectic souls. The new age movement has totally swallowed that old Christian groove. There are even pop versions of it - the group ‘Enigma’ has made a very healthy living from it.
But overall have you heard one Kyrie Eleison you heard them all.
More? Kyrie @ Wikipedia