《论衡·卷五·感虚篇》
有人说： 师旷的《清角》曲，开始演奏，就有云从西北面升起；再次演奏，大风来，大雨随之而到，吹裂帷幕，砸坏俎、豆，把廊上的瓦刮了下来，坐着的人纷纷逃散。
或言师旷《清角》之曲，一奏之，有云从西北起：再奏之，大风至，大雨随之，裂帷幕，破俎豆，堕廊瓦。坐者散走。
It is said that: When Shi Kuang played the "Clear Angle" tune, clouds rose from the northwest at the beginning of the performance; when he played it again, a strong wind blew and heavy rain followed, tearing the curtains, smashing the俎 and 豆, and blowing off the tiles on the corridor. The people sitting there fled in all directions.