Composed by Wang Huiran in 1960.
The Yi people are one of the officially recognized 55 Chinese ethnic minorities.
A Jackdaw is a type of crow: en.wikipedia.org/wiki/Western_jackdaw
Considered one of the 10 famous Chaozhou music pieces TODO list.
Was also adapted by Liu Baoshan (1937-1997) as a pipa song. Ciro Santilli prefers the pipa version.
Bibliography:
A Baidu Baike page: baike.baidu.hk/item/層層水瀾/12386243 mentions that the score was published in 1970 by Tao Yimo (陶一陌) in a eponymous score book.
www.ibiblio.org/chinese-music/html/traditional.html contains an amazing orchestral version for di flute TODO identify! When attempting to upload to YouTube, it identifies as "Su Wu Tending the Sheep" and give a name "Chen Tao", but no further information. Chen Tao is presumably this dude: www.barduschinamusic.org/chen-tao-dizi | www.melodyofdragon.org/chentao.html 陈涛
baike.baidu.com/item/苏武牧羊/5532#11_2 mentions that it comes from an erhu concerto composed by Peng Xiuwen
The sadness of the erhu perfectly fits the role and mood of the story! Brilliant!