I Hear Four Symphonies

I keep thinking about this podcast of WNYC's Radio Lab called Shorts-a 4-Track Mind from July 26, 2011.
. . . about a man who can hear four symphonies at a time. Evidently, they tested him by giving him a few days to memorize 4 symphonies: a Brahms, Mendelson, Beethoven, and Schubert.
Then they put him a sound-proof room by himself and told him when each symphony was beginning--and to start listening to them in his mind. (The symphonies were actually playing in a control room.) At arbitrary times they asked him what was happening in each symphony.
He could say precisely what was happening in each symphony, down to the exact notes and instruments . . .
How does he do this? They don't know.
But he says he hears music as emotion. C major, for example, is like eating water soup. D minor makes him want to dance.