Peter Ablinger is new to me. He maybe inherits from Cage & Feldman, but I find his music more rewarding to listen to. Lately he has been working with piano "transcriptions" of human speech.
Slightly older music: the Berio Sequenzas, Xenakis, and an older but beautiful Milton Babbitt CD. The download of the Jack Quartet playing Xenakis is the price of a hamburger.