The Beat Will Set You Free
[O]ur perception of the external world entering our mind through our eyes is affected by the rhythm of what we hear. Something seen at a point precisely in beat with an auditory rhythm is more likely to be perceived than if it appears out of synch with the rhythm. This gating of visual input by auditory rhythm does not require a prolonged meditation on the rhythm to cause the person to enter into some sort of a trance-like state; the effects are nearly instantaneous.
Psychologist Annett Schirmer has presented findings on her study of how music affects human cognition, particularly visual perception. According to her research, brainwaves in the region associated with early vision processing not only synchronize with a musical beat, but they also peak higher when a beat is present compared to when not. I'm too tired to write up a proper synopsis for you, but the idea is exciting and exceedingly interesting. You can read about it in this Scientific American article: The Power of Music: Mind Control by Rhythmic Sound.