In oracle bone inscriptions, new and old "xi", means ancient and modern music; "gu" means blind people; "yong" and "mei" refers to ode and refined poem respectively.
卜辞中有"丐",当读为瞽,指盲人。
There are some discussions about the forming Zuo Zhuan,including oral narratives of history of Gu.
《左传》成书的讨论很多,其中有瞽史口传一说。
The New Discussion of Shen-gu;
神瞽新说——兼论成相之起源
On Tsunzi s Cheng Xiang from History and Culture of the Blind:More Comments on Cheng Xiang for Folk Song Style;
从瞽史文化看荀子《成相篇》——兼评《成相篇》为民歌体