UbuWeb is hosting a massive collection of electronic and electroacoustic songs from 1937-2001.
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.
(via open culture)
Update: The tongue-in-cheek Flash-only interface is terrible, but if you get past that, Ishkur's Guide to Electronic Music is an amazing resource. (via @xRageous)