"知己“=someone who understand you as a person "知音”=someone who appreciate your talent

知音 源自於一個故事 春秋時代，俞伯牙善鼓琴，鍾子期善聽琴。 當伯牙彈琴志在高山時，子期便從琴音感到峨峨若泰山； 當伯牙志在流水時，子期又感到洋洋若江河。 子期死後，伯牙便絕弦不彈， 因為再也沒有人能像子期那樣懂得他的音樂了。 故事見列子˙湯問。 後比喻了解自己的知心朋友。 文選˙古詩十九首˙西北有高樓：「不惜歌者苦，但傷知音稀。」 三國˙魏˙曹丕˙與吳質書：「昔伯牙絕絃于鍾期，仲尼覆醢于子路， 痛知音之難遇，傷門人之莫逮。」 知音相似詞 : 相知、知己、知交、知心 知己: 相互了解而友誼深厚的人。 唐˙王勃˙杜少府之任蜀州詩：「海內存知己，天涯若比鄰。」 相似詞: 密友、老友、好友、心腹、相知、知交、知心、知友、知音、摯友

知音与知己大意相同，但还是有一点小区别。知音源自第一楼所描述的故事。知音，原意是通过音乐了解彼此的内心，音乐是全世界共通的语言。知己，可以解释为能够了解你、理解你的好朋友。

知己=>best friend 知音=>best frienf forevereverever And there's a "best friend forever"between them

sometimes we think they are the same" 知己"and " 知音",both of them means sb knows you ,understands you so well ,he knows what color you like ,what kind of books you prefer ,or maybe what kind of men or women you will love.but if someone is already your best friend ,you usually say he is your"知己", "知音" can be used on a person maybe you two are totally strangers. "知音" comes from a ancient chinese story,"音"means "music"(音乐)，“己”means "myself“（自己）.the story is about two men they knew each others' music talent very well.