“Horsetamer’s Daughter” is set in Marion Zimmer Bradley’s Darkover universe, and is really a fanfic in its own right. It was originally written by Leslie Fish, and is infamous for going on… and on… and on… and…
(Probably apocryphal) legend has it that when presented with the song, Marion Zimmer Bradley told Leslie Fish something along the lines of “That’s nice, dear, but isn’t it a bit long?”
Lyrics are available here.
(Source: https://www.youtube.com/)