《文心雕龙·声律》
声韵要如咸盐酸梅配合得当，把榆实、堇菜调和得味美可口；只要摈除那些不正之音，和谐的宫商就自然明显。
声得盐梅，响滑榆槿。割弃支离，宫商难隐。
The vocal tone should match that of salty sour plum to provide a palatable flavor for elm seeds and violet vegetables; as long as improper tones are excluded, harmonious combination of Chinese music would be naturally apparent.