Hard graft, not genes.
From the New Scientist : WANNABE rock stars: keep practising. Yet more evidence has emerged that musicians are made through training, not born with the gift. We already know there is something special about the way musicians' brains react when they hear music. Now new scans have revealed that specific regions of the brain dedicated to musical syntax and timbre become even more animated than usual in musicians when they hear recordings of their own type of instrument. Elizabeth Margulis at the University of Arkansas in Fayetteville and her colleagues noticed the distinctions when playing music to flautists and violinists: only when the musicians heard their own instrument did these areas show this boost in activity. ...