Help me solve the mystery of Stephen Stills' accordion

I'm writing a biography of rock star Stephen Stills and I cannot find any reference as to why the Stephen Stills refence is in the movie Prometheus. Is Ridley Scott a fan? I assume he was responsible but the only interview online I could find that might address this issue has Ridley Scott being asked this question and another phone ringing and him never answering the question... Any ideas?