Music - the wonder of it - how did it evolve?

This is way outside of my field, but fascinating to me.  There was a piece in the Washington Post the other day on music - why we like it so much. It was by Carolyn Butler, and you can find it here:
http://www.washingtonpost.com/wp-dyn/content/article/2011/02/28/AR2011022806231.html.

It turns out, music turns on our brain - really.  We get a shot of dopamine when we listen to music we like.  It can be any kind of music that we enjoy.  We anticipate the next part, the beat, the cadence - it turns us on, literally.

The author notes that there is no accepted theory for the cause of this evolutionary miracle.  Most evolutionary traits that were developed by evolution have to do with survival and sexual selection.  It seems obvious to me how this feature  evolved - but on looking it up, there are apparently no good theories on why we acquired this amazing feature.

There is a wonderful, scholarly review of all of this available on the web here:  http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.106.6746&rep=rep1&type=pdf.

This is cited by 98 sources, and it is a good survey of the field of knowledge on this.  If you skip to page 199, the author summarizes the discussions on the evolutionary imperative to endow us with this amazing gift of music.  To summarize briefly:

1. No adaptive function at all - seems highly unlikely to me.
2. Cheesecake - we created this just to enjoy it - it doesn't have any adaptive function.  Similarly unlikely, but hey, whatever works.  I like cheesecake too.
3. Byproduct of language development.  Well, it's certainly connected to language, and we are one of the few species with both skills!  But I think this needs a little push yet.
4. Sexual selection.  I dunno - it seems to work for birds and frogs - and it may be part of the origin of this, but I don't think this highly developed skill works all that well in attracting mates.  Didn't work for me, anyway.
5. Group function - kin selection. Dancing and music certainly generate group interaction and cooperation - amazingly well.  I think there is an element of the adaptive function here.
6. Mother / Infant song.  That works really well too, but I think it is still missing the key point.
7. Music as play.  Yep - no denying it - but how adaptive is that?  It's important to learn basic things as youngsters, like wrestling, hunting, etc.  And music is a key skill - but what is the adult return for this development?

The answer - well, this is mine anyway.  It's a combination of the above in this way:  humans learn things orally, through song and rhyme and rhythm.  Before we invented writing, we passed on wisdom and practical knowledge and myth and values orally.  We sat around fires and hearths for hundreds of thousands of years, and told stories and sang songs.  Homer and the Bible are clear examples of what was passed on from generation to generation in poems and songs.  We love stories, we love songs.  If you didn't learn them, then you could not remember how to hunt the beast, or how to build a house, find the edible plants, or how to negotiate a bride - your genetics did not survive.

Why do you think those songs get stuck in our ears and brains?  That is how we were taught to do everything before we invented writing.  It is still an amazingly effective learning method.  But I think we have forgotten how to use it to teach and pass on wisdom.  We have popular songs that are not helpful, to say the least.  The religious stuff we are normally exposed to is of no help either.  It rarely focuses on our current behavior and the wisdom of our time.  It is all wrapped up in  myths and stories.

I love baroque and classical music -- and it does lift me up.  But it doesn't teach much.  I've learned more from Bob Dylan and Peter Paul and Mary than Beethoven and Bach.  I'd like to see a revolution in song that emphasizes learning and cultural values that are more uplifting, ennobling and supportive of human development and freedom.  Does anyone have a catalogue of those handy?