There was a time in the 80s when you could pick up a TB-303 or a TR-808/909 for $20 -- nobody wanted them! The 303 didn't sound like a bassline. The 808 certainly didn't sound like actual drums. And the people buying them weren't classically trained musicians: they were dudes who liked the music and wanted to try it themselves.

There's a documentary I really like on the history of House music called "Pump Up The Volume," and it can actually be found entirely on Youtube: http://www.youtube.com/watch?v=Y1HpY65cXDA -- it covers what some of the early genre originators were doing and feeling at the time. Generally they were just experimenting, as well as doing the "track -> venue/club -> evaluate" feedback loop so common in the origin of genres. However, I still think it's cool to hear them discuss their unique contributions to a style that would eventually grow far larger than they ever expected.

There are also some good books on the history of electronic music I can recommend, the best one being "Last Night A DJ Saved My Life" http://www.amazon.com/Last-Night-DJ-Saved-Life/dp/0802146104...