Ambient music is a musical genre where sound is more important than notes and is recognized by its environmental and atmospheric feel. The main effect of this kind of music is to drift in and out of the listener’s awareness. This genre came from early 20th century forms of “semi-audible music”, from Erik Satie’s impressionism, through Terry Riley and Philip Glass’ minimalism of concrete music and Brian Eno’s deliberate sub-audible approach. During later times, ambient music is applied to rhythmic music at raves and dance events.