Techno is a genre of electronic dance music that emerged in the mid-to-late 1980s in Detroit, Michigan, United States. It is characterized by a repetitive 4/4 beat, synthesized melodies, and the use of drum machines and other electronic instrumentation. The genre has evolved over time and has many sub-genres such as Acid techno, Ambient techno, Detroit techno, etc. Techno music is often associated with nightclubs, raves, and electronic dance festivals.