The Learning Point
The proverb "对牛弹琴" is used by Chinese people to describe someone who is telling something complicated to the fool, or sometimes this idiom is used to describe a person who is trying to tell something to the wrong audience or listener. In English, people sometimes joke around by ironically saying "whistle jigs to a milestone" or "cast pearls(a hard round object which is shiny and creamy white in colour. Pearls grow inside the shell of an oyster and are used for making expensive jewellery) before swine" to mean "对牛弹琴."
The Chinese Story of Proverb
战国时代，有一个 叫公明仪的音乐家，他很会弹琴。很多人都喜欢听他弹琴，人们很敬重他。一天，公明仪在郊外游玩时，看到了一头牛。他想：大家都赞扬我的琴技，不如我给牛也弹一曲吧! 他给牛弹奏了一曲古雅的曲子，牛埋头吃草不理他。他又弹奏了一曲欢快的曲子，牛依然埋头吃草不理他。公明仪拿出自己的全部本领，结果牛还是不理他。公明仪非常失望，开始怀疑自己的琴技。路人说：“不是你弹的琴不好，而是牛根本听不懂啊!”
In ancient times, there lived a musician named Gong Mingyi. He was a master of the Zheng, a plucked string instrument. Unfortunately, his rash behavior often led him astray. One day, he saw a cow grazing in a field near his house. He was inspired by the scene and ran outside to play a tune for the cow. Gong Mingyi played beautifully, finding himself intoxicated by the music. But the cow paid no heed to the elegant sounds, simply focusing its attention on eating the grass. Gong Mingyi was surprised at this and could not comprehend the cow’s flippant indifference. He felt that since his performance had been masterful, this means that the cow neither understood nor appreciated his elegant music! From that story comes the idiom “To play the lute to a cow”(对牛弹琴duìniú-tánqín), which implies that someone speaks or writes without considering his audience. Generally speaking, it means the speaker or writer has over-estimated his listeners or readers. In these cases, the idiom mocks the audience rather than the speaker.