Crystal singer trilogy

Killashandra Ree has spent ten grueling years in musical training, anticipating interstellar celebrity as a vocal soloist. She is young, beautiful-and still without prospects. After learning that a flaw in her voice will prevent her from singing lead, she hears of the mysterious Heptite Guild on the planet Ballybran, where the fabled Black Crystal is found. Mining this strange form of crystal is a dangerous occupation but to Killa, the risks are acceptable....

Killashandra, one of the most gifted singers on Ballybran, is drawn like a magnet to the song of crystal. In order to work with crystal, singers are infected with a symbiotic life form that heals them and gives them near eternal life-but slowly destroys their memories. Since crystal singing brings Killashandra ecstasy, she doesn't mind the initial small annoyances of memory loss. What she hadn't counted on was the loneliness she felt when her heart...