chance music - the music is silent, and the performance consists of whatever sounds occur during that time frame a person coughing, feet tapping, a car horn outside whatever.
In the 1970s, electronic music began to have a significant influence on popular music, with the adoption of polyphonic synthesizers, electronic drums, drum machines and turntables, through the emergence of genres such as disco, krautrock, new wave, synth-pop, hip hop and EDM.