Anne McCaffrey first wrote about Killashandra in a serialized short story. She expanded the story in Crystal Singer,which is the first of a trilogy of novels.
Killashandra fails her final exam in music school and faces a life of second-billing as a choir soloist and not a top performer as she had dreamed. She will not settle for second place, and impetuously takes off with a mysterious companion for Ballybran, a forbidden planet with an alluring secret.
Ballybran is the home of Crystal, which is mined and used for vital starship drives, interplanetary communications systems and most other types of equipment. It is controlled by the powerful and secretive Heptite Guild. Killashandra applies for membership and is accepted. She goes through the intensive schooling and special adaptation to become a Crystal Singer.
But singing Crystal has not only its rewards (and they are many) but its heavy price. Killashandra learns about the price as she becomes a full-fledged member of the Heptite Guild and becomes involved with its enigmatic Guildmaster Lanzecki.
This is one of those wonderful kinds of sci-fi novels that can create an entirely new world, complete with its slang, customs and characteristics. It's sci-fi at its best.