Whenever a noise exceeds our processing abilities--we can't decipher all the different sound waves hitting our hair cells-- the mind . . . stops trying to understand the individual notes and seeks instead to understand the relationships between the notes. The human auditory cortex pulls off this feat by using it's short- term memory for sound (in the left posterior hemisphere) to uncover patterns at the large level of the phrase, motif, and movement. This new approximation lets us extract order from all those notes haphazardly flying through space, and the brain is obsessed with order . . . It is this psychological instinct--this desperate neuronal search for a pattern, any pattern, that is the source of music . . . We continually abstract on our own inputs, inventing patterns in order to keep pace with the onrush of noise. And once the brain finds a pattern, it immediately starts to make predictions . . . It projects imaginary order into the future . . . The structure of music reflects the human brain's penchant for patterns . . . But before a pattern can be desired by the brain, that pattern must play hard to get