“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.
I am the daughter of a poor estate.
With no dowry there’s no man who’d have me as wife.
The tower called out so gently to me,
Said a keeper’s oath would set me free.
The years pass by, and the nights and the days,
And the people may change but my works stays the same.
Though I love them well they leave anyway,
While here in the tower alone I stay
“Keeper’s Lament,” by Anne Harlan Prather, based on Marion Zimmer Bradley’s Darkover novels