I can hear Bobbi Joy's voice. She's a fictional character and has never existed, but I can hear her voice, and I can imagine how the tune might have gone.
Spider Robinson is no slouch of a singer/songwriter, himself, and he's tackled The Drunkard's Song with his guitar, so that we, as fans, know what that song, at least, would have sounded like.
But I don't think he'd try either of Bobbi Joy's songs. Probably every fan has a slightly different take on what she would have sounded like, and if he made a canonical version he'd be disappointing almost everyone who imagined her as being slightly different.
Still... I wish I could order one of her CDs. I'd like to listen to it.