What Makes a Musical Expert?

How does someone become expert in music? And IS it really possible to have a ‘talent’ for music? A Does that class of people acknowledged to be musical experts just have more of the same basic skills we are all endowed with, or do they have a set of abilities - or neural structures - that are totally different from those of the rest of US? Are high levels of musical achievement simply the result of training and practice, or are they based on innate brain structure - what we refer ...