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Composed between 1985 and 2001, these 18 etudes are widely considered the most important collection of piano studies since Debussy and Chopin. They are the "Mount Everest" of contemporary piano literature—brutally difficult, but utterly mesmerizing.

Ligeti was obsessed with the music of Conlon Nancarrow (player piano rolls). He tries to replicate mechanical canons where the two hands are slightly out of phase. Try counting this: the left hand moves in a 4:5 ratio against the right. Your brain will hurt. A Practical Tip for the PDF If you have acquired a legal copy of the score, do not just print it on standard paper. Take the PDF to a print shop and have them blow it up to A3 (or Tabloid 11x17).

If you are a pianist, you know the feeling. You hear a flash of impossible speed, a bizarre rhythmic hiccup, or a hauntingly beautiful melody that seems to glitch out in real-time. You look at the score and realize the sheet music looks like abstract art.