Bert - I thought it was a pattern recognition thing too. It was the bit about taking away the music & everything else being unchanged which made me think it. I think that in the same way that all the pictures we are surrounded by give us a basis & framework for recognising visual pattern in the real world (I'm not saying that's all they're for mind you) - I think that music gives us a framework for recognising aural patterns (pitches & rhythms)in the real world. Maybe like a mental language in which to think in sounds - which would help in recognition & remembering sounds, all of which must have a survival advantage. Again I don't think that is all its for though!

Kris