What are the twelve ancient rhythms?

The rhythm of ancient Chinese music was divided into five tones by the method of three points of loss and gain, i.e., Gong, Shang, Horn, Zheng, Feather (i.e., 1,2,3,5,6 nowadays), and later developed to seven tones (i.e., 1,2,3,4,5,6,7 nowadays). Later, in order to harmonize the music and rotate the palace, the twelve-tone system was established at that time, that is, the yellow bell, dalu, taijiu, jiaozhong, gushu, zhonglv, lege, linzhong, yizhe, nanlv, wuzhuang, yingzhong, that is, the twelve-tone system, which is what we usually refer to as the twelve-tone system.