I say nurture it! My DH was described just like your son. His mom would take him into record stores when he was two and he would name all of the artist on album covers and talk about their songs. He would spend hours spinning records on pencils and singing and drumming on things. His early music obsession has lasted his whole life. He has a vault of music knowledge that is staggering (always have him on your team in trivia games!). Sadly, his parents would chuckle at him but they never nurtured his love of music. He was not offered any music lessons. He now plays two intruments well... completely self-taught. He spends a good portion of his day listening to music, talking about it, researching it or playing it.
As an aside, he has NO traits of Aspergers. Just an extreme love of music (and maybe a little ADHD?).
