In today's New York Times, Clive Thompson sketches ("Music of the Hemispheres") an argument from Daniel Levitin that listening to Mozart cannot enhance one's intelligence.
Levitin argued that this could not be true, based on his study of people with Williams syndrome, a genetic disorder that leaves people with low intelligence. Their peak mental capacities are typically those of a young child, with no ability to calculate quantities . . . . Yet people with Williams possess unusually high levels of musical ability . . . . Music cannot be indispensibly correlated with math, Dr. Levitin noted, if people with Williams can play music.
Well, no, but that says nothing about whether listening to Mozart can enhance one's analytic abilities. It is quite possible that parts of the neurological pathways used for mathematical computations and analysis are shared with the pathways used in interpreting music. If the non-music parts of these pathways are weak in Williams people, no amount of listening to music will help them. However, if the music parts of these pathways are weak in non-Williams people, but not the rest, then listening to Mozart could have a dramatic effect for them. (It would be a surprise to me, however, if it were ever proved true that something as passive as listening to music has a lasting effect on the brain.)
It's possible, of course, that Thompson has overstated Levitin's position. But there are weak and bizarre arguments aplenty in the field. Nicholas Humphrey's assertion that sensation and perception are two independent things that happen in parallel is an odd one (see John Searle's discussion in the New York Review of Books, Volume LIII, Number 17). Daniel Dennett's feeling that denying that subjective experience exists is sufficient to dispense with it is a weak, if surprisingly popular, position.
Incidentally, CNN reports that President Bush listens to baby-boomer tunes.