12 lü

…open ends, they produced the 12 lü, or fundamental pitches, of the octave. These pipes should not be confused with the panpipe, or paixiao.

…writings on music discuss a 12-tone system in relation to the blowing of bamboo pipes (lü). The first pipe produces a basic pitch called yellow bell (huangzhong). This concept is of special interest because it is the world’s oldest information on a tonal system concerned with very specific pitches as…