Imagine being able to listen to four songs at once and not having is just be a cacophony of noise. Some people can listen to two songs and understand what they're listening to, but Bob Milne can hear four separate songs at once, and keep track, note for now. He's also considered to be the best ragtime/boogie-woogie pianist in the world and he's a self-taught player.
Give this short podcast a listen. It features Milne taking on the date of a neurologist against a ragtime player piano. It's an unreal feat.