Ubu Web is a great resource for “avant-garde, ethnopoetics, and outsider arts” (as they put it).
One of their many treats is History of Electronic / Electroacoustic Music
476 tracks for your listening pleasure.
There are some caveats:
This is from a 62 CD set called “The History of Electroacoustic Music” that was floating around as a torrent, reputedly curated by a Brazilian student. It’s sketchy. The torrent vanished and the collection has long been unavailable.
It’s a clearly flawed selection: there’s few women and almost no one working outside of the Western tradition (where are the Japanese? Chinese? etc.). However, as an effort, it’s admirable and contains a ton of great stuff.
Take it with a grain of salt, or perhaps use it as a provocation to curate a more intelligent, inclusive, and comprehensive selection.