Drone music
（重定向自Dronology）
Drone music, drone-based music, drone ambient, ambient drone, or simply drone, is a minimalist musical genre that emphasizes the use of sustained or repeated sounds, notes, or tone-clusters – called drones. It is typically characterized by lengthy audio programs with relatively slight harmonic variations throughout each piece compared to other musics. La Monte Young, one of its 1960s originators, defined it in 2000 as "the sustained tone branch of minimalism".