"To be versed in the ceremonial usages, and not versed in music, we call being poorly furnished. To be versed in the usages and not versed in music, we call being one-sided." (sacred-texts)

At first I thought this error might happen in some stages from scanning to text, since all text on the internet are same, I check with against the original images of the book, and realized it's the error of J. Legge.

Apparently these two sentence is a comparison of two defects of  a person, who was to be versed or not with ceremony and music. Then Confucius applied this general rule to the ancient musician Khui, saying he just a musician versed with music, but not ceremonial usages, that's why he couldn't be called a sage or superior-man. 

The original Chinese text reads as below:

The right rendering the the text should be like this:

"To be versed in the ceremonial usages, and not versed in music, we call being poorly furnished. To be versed in music and not versed in the ceremonial usages, we call being one-sided." (The Book of Rights)