listen:

Ussachevsky, Wireless Fantasy (1960)
Yuasa, Projection Esemplastic For White Noise (1964)
Oliveros, Bye Bye Butterfly (1965) - more info here
Tudor, Rainforest Version 1 (1968) - more info here
Xenakis, Hibiki-Hana-Ma (1970) - more info here
Spiegel, Appalachian Grove I (1974) - more about Laurie here
Lansky, Six Fantasies On A Poem By Thomas Campion: Her Song (1978) - more info here
Anderson, O Superman (1981) - more info here
Eno, Lantern Marsh (1982) - more info here
Amacher, Stain - The Music Rooms (1989?)