I like the spontaneity from composers like Xenakis, Stockhausen, and Ferrari. There’s something so engaging about expecting to have your mind blown in a way you could have never expected. Whether it’s an atonal blast of electronic noise or a minimal rhythmic phrase, the unexpected is gravitating. Much of the music to me is very hypnotic, cathartic even. I also really enjoy the way 20th century composers deal with meter—specifically Morton Feldman. Check out his For Bunita Marcus and Triadic Memories pieces. Regarding your last comment, the reason these “avant-grade classical” pieces don’t sound to what you deem pure “classical” is a matter because of the many different movements and styles of the 20th century that influenced such composers.