Japanese to English Art/Literary Music

This is from a paper about comparing folk songs across cultures. It was translated originally from Japanese, but I only have the English translated document to look at.

But unlike the Western cultures, which are organized horizontally, Japanese culture has a vertical structure. With regard to studies of development and change in Japanese music, the musical traditions exist independently of one another, each passing down its own repertoire from generation to generation with very little exchange between other traditions (i.e. iemoto system, hiden, kuchi utsushi).

1. What are the Japanese characters for "kuchi utsushi"?
2. And what is a brief English explanation for "kuchi utsushi" in this context?

Thank you.