There was this awesome novel I read about a decade ago but can't remember the title. I'm certain it had "Stars" in the title. It was older, maybe 60s or 70s. It was about this boy and his life in space. He joined a traveling "space circus" and learned to play this magical mandolin looking instrument which is also on the cover. He used the mandolin later in life to save a planet and stuff, again, a decade ago I don't remember it all. It sounds psychedelic, but it drew you in and was a wonderful read. The cover was bright green and had a picture of the character with the mandolin. I want to buy the book and read it again, but that would require the title and my memory to not epically fail me. Google has proved useless. Anyone know what I'm talking about? Thank you!