I did an album a long time ago called 'Replicas ' which was entirely science-fiction driven or science-fantasy. Since then it's been a song here a song there. It's not really a constant theme. I've written far more about my problems with religion with God and all that.
I did a cake for the 60th birthday of Elton John for Britney Spears' 27th birthday and for the 'Circus' album she put out - the cake had circus themes. I prepared a cake for a surprise 82nd birthday event for the architect Frank Gehry the cake was comprised of mini-replicas of his buildings.
When you sing with a group of people you learn how to subsume yourself into a group consciousness because a capella singing is all about the immersion of the self into the community. That's one of the great feelings - to stop being me for a little while and to become us. That way lies empathy the great social virtue.