Music Makes Us Human
I've been reading Daniel Levitan's <I>The World in Six Songs: How the Musical Brain Created Human Nature</I>, which makes pretty strong claims for the importance of those tones in time. (Neil McCormick conducted an interesting <A HREF="http://blogs.telegraph.co.uk/neil_mccormick/blog/2009/04/09/evolution_o…; with Levitan in <I>The Telegraph</I>.)