Techno, or "rave" music is a style that gets its roots from the broad use of analog synths in the late 70s. Recorded samples are used to great effect, and the music is typically repetitive in theme, but constantly growing to an energetic peak. Most often recorded onto vinyl, DJs who play at raves mix songs together, such that the music is continuously played for hours at a time, creating a trance-like effect on those listening. It's a lof of fun, you should try it sometime.