Ping is what I do when I flick my finger on some chicks ass.... and thump, bang, clunk is what I get back for being too darned
sassy. 
True. A resonance unique to each one. There's a classical piece, I don't know the name of the author, that is called The Song of the Planets. NASA actually recorded the sounds made by the sun and planets.
That's very interesting indeed... might have to investigate when I'm less underwhelmed. 