So, what's the purpose of music

You would think it is easy to explain.

Some evolutionary psychologists suggest that music originated as a way for males to impress and attract females. Others see its roots in the relationship between mother and child. In a third hypothesis, music was a social adhesive, helping to forge common identity in early human communities.

That's nice. Can the evlutionary psychologists prove it?

``They're completely bogus explanations, because they assume what they set out to prove: that hearing plinking sounds brings the group together, or that music relieves tension," he [Steven Pinker] says. ``But they don't explain why. They assume as big a mystery as they solve." Music may well be innate, he argues, but that could just as easily mean it evolved as a useless byproduct of language, which he sees as an actual adaptation.

From the essay Survival of the harmonious at the Boston Globe.