《庄子·外篇·天运》
因而乐声象是混同驰逐相辅相生，犹如风吹丛林自然成乐却又无有形迹；传播和振动均无外力引曳，幽幽暗暗又好象没有了一点儿声响。
故若混逐丛生，林乐而无形，布挥而不曳，幽昏而无声。
Thus, the musical sound and image are mixed up and chasing after each other, supporting and giving birth to each other, just like wind blowing through a forest, naturally forming music, yet without any sign; the spreading and vibrations are not pulled by any external force, obscure and dark, and it seems as if there is no sound at all.