I have a few ideas about music and sound in relation to reality. Why do animals sing and dance (and fight) for a mate? The correlations between that behaviour and our own dancing and singing in ballrooms and dance halls all around the world is not just a co-incidence, its an evolution of basic animal behaviour. Birds and other colourful animals have evolved their colours to attract a partner. As humans we can choose to wear whatever we want, and the change in colour can match our mood. This is exactly the same situation in song and dance. Imagine if all we could sing and dance to was one song, and by sods-law it was the chicken song lol. It would be hell. Luckily we have evolved minds and tools to be able to create our own appearance and choose our favourite songs, its the same process though its now sped up to match our evolutionary path.
But back to the human nature element, its not just chance that women have sang to their children to sooth them. It seems we are susceptible to musics effects on our mind and body. Snake charmers play that flute thing and the serpent seems mesmerised by it, dancing its way out of a basket. The truth of it though is its reacting to vibrations, it doesn't 'hear' the music at all. It can't be only me that has had a favourite tune and had hairs on the back of my neck stand up, or become emotional from the lyrics of a song. Even movies would be totally lacking in depth without the musical scores to go with them. Next time you see a horror movie and that pre-scare music comes on, ask yourself how much you're afraid because of the picture and how much because of the sound...
Songs definately have an impact on emotion and behaviour, at least short term. It was found that peolpe listening to Rock/Metal/Dance music are heavier on the pedals when driving than people who listen to classical and easy listening - so thats a behaviour effect. Long term, I suppose a person who has no friends and constantly listens to Dr. Dre or Eminem as comfort, would start to have semi-distorted views on whats right and wrong, but that would probably be due to the anger reinforcing those views. Listening to depressing music is also shown to deepen the depression, and likewise happy music when your happy actually helps to increase the feelings. Its not recommended now, but I actually prefer listening to sad songs when I'm sad and happy when I'm happy, so I can increase the depth of my experience while alive.
The vibrational energies that create sound are also responsible for form. This brings new light to the Far Eastern concept of AUM/OM and 'In the beginning was the word'. The reason they chant Aum over and over is to resonate the mind and help ease it into other states of conciousness ie trances. Rythmn can also be used to create altered states, which is why drumming is often used in rituals. I think its not unreasonable to think that we are tuned into our current mind-channel because of the external and undetectable background frequencies in the Universe, cosmic background radiation for instance.
Check out cymatics for more details on the link between sound and form. For additional evidence, the Hexagon in Saturns atmosphere is enough for me. But the frequency for columns of hexagonal rock to form at Giants Causeway and similar is much higher than any other polygon. Bee's forming hexagonal honeycombs and the fractal hexagonal shapes found in the classical images of snowflakes should be taken as hints that the Universe is gently humming at a frequency that creates these forms ever since the Big Bang.
If you want to take a totally metaphysical and geometrical example then check out the male-female triangles (holy trinity x 2) of fire and water in alchemy, they came together to form the Star of David and in a way encapsulate a lot of what religion is all about. The fact these symbols appeared in our culture should not be taken lightly and as simple human creativity, there is no lines of division between us and the Universe, in Quantum physics or true religious belief.
Finally, what Max said