They're not that tonal to my ears. Ligeti himself said they are neither tonal nor atonal. I think the rhythms and range are what's most notable about...
much like law, social roles, currency, and nations, things fundamentally being based on subjective consensus doesn't mean they aren't capable having...
I rank Chopin over Schumann by a hair, but honestly not by much. Schumann took a long time for me to understand - more than three years of listening....
