Alex Rehding, Professor of Music at Harvard, emails Jonah Lehrer:
If we derive pleasure from anticipating potential connections - and especially being surprised by thwarted expectations - then it becomes difficult to explain why we would want to listen to a piece more than once: the novelty factor wears off, the uncertainty factor becomes less pronounced. In principle, the piece should get less interesting each time we hear it. Experience, however, shows that this is not the case: we greatly enjoy re-hearing familiar pieces. The whole recording industry makes a lot of money on the basis of this phenomenon.