I enjoyed the Clarke's super intelligent aliens not being able to understand what we experienced in music. I also was somewhat surprised by the statement that music served no purpose what so ever in our survival. I am not sure that I totally buy that. That is not to say that I believe that people who go to concerts or can play a guitar are going to have a greater chance survival than those who don't but it seems to be an awfully complex mechanism just to spring up out of the woodwork of our brains. My guess would be that music may be related to the sing songy baby talk that adults use to communicate with infants. There is a Radio Lab program about this very subject.
http://www.wnyc.org/shows/radiolab/In the above website, look at the episodes window on the right side of the screen. Move the slider down about 2/3 of the way until you see Musical Language. It is quite interesting. If I remember correctly it is about an hour long.
The alien thing is interesting to me because some where I read recently a very similar notion regarding vision. If we were to see the world as it really is it would be pitch black with a whole bunch of emitted and reflected electro-magnetic waves of various intensities and frequencies. There would be no colors, no shades of colors, no objects, nothing visually intelligible. Just a highly variable collection of electro-magnetic energy in pitch black. Which seems surprising but think of it do you see a flash when you get an x-ray? Do you see heat coming from an oven? The only difference between the x-ray, visible light, and infra-red is the frequency (ergo wavelength) and the amount of energy in the photon. Visible light is no more inherently visible except to those who have the receptors sensitive to those wavelengths and the brains to put together an image out it. So it is with audible air pressure waves, there is nothing inherently audible about them unless you got the equipment. Such easy functions for us, yet when you think about how purely amazing it is that we can see a rich world of color, movement, and detail with nothing more than our eyes and brains and do roughly the same with sound and our ears... the notion just floors me!