Pierre Schaeffer locked himself in a studio with train recordings. He rejected sheet music and synthesizers: "The material of music is sound itself." Thus was born Musique Concrète: a collage of reality, created with scissors and tape.
node.music - an interactive map of the history of electronic sound
From the Telharmonium, which streamed sound over telephone wires at the end of the 19th century, to music written by AI.
Scroll down - that is how you move through time in a straight line. The [INFLUENCE] mode in the top menu reveals connections: who begat whom and how concepts shaped each other. To explore the influences deeper, switch to [HORIZON VIEW].
The site makes sound - and you can even play on those sounds. If the sound gets in the way, just turn it off in the top menu.