There's experimental evidence -- summarized here by K. Anders Ericsson, an expert in this field -- that virtuosity in playing a musical instrument has less to do with innate talent than with the number of hours of practice put in. This topic's been featured heavily in some popular books recently, including Malcolm Gladwell's Outliers.
Ericsson -- "the critical difference between expert musicians differing in the level of attained solo performance concerned the amounts of time they had spent in solitary practice during their music development, which totaled around 10,000 hours by age 20 for the best experts, around 5,000 hours for the least accomplished expert musicians and only 2,000 hours for serious amateur pianists. More generally, the accumulated amount of deliberate practice is closely related to the attained level of performance of many types of experts, such as musicians... chessplayers... athletes..."
Gladwell goes to town with the 10,000 hours idea, claiming for example that the Beatles were so good because they played for 10,000 hours in Hamburg before they became famous. But he fails to ask what exactly the Beatles were good at -- it's not that they were the greatest guitar virtuosos of their time, or that Ringo was the greatest drummer. Virtuosity in playing one's instrument is simply not as important in popular music as it is in classical music.
Nor were the Beatles the greatest singers of their time. Perhaps they were the greatest popular songwriters? But their songwriting isn't what they spent 10,000 hours practicing in Hamburg. Maybe part of what they were so great at was precisely playing together, as a band? But how much of their success was due to their being good-looking, or just the right amount of cool/edgy, or to their music being just different enough from the rock music that was already popular, or to other attributes that 10,000 hours wouldn't have done much to enhance? How does the 10,000 hours theory explain the not-especially-distinguished solo careers of certain ex-Beatles?
I don't think the 10,000 hours idea is much help for explaining which popular musicians are successful.
Are writers more like classical musicians, in this respect, or more like popular musicians? John Crowley is a great writer, someone you'd think would know, and he doesn't entirely buy the 10,000 hours idea for writers.
"I tell the most talented writers I talk to to remember that if they stop now, don't write another word or think about writing for the next five years, they will be better writers at the end of those five years than they are now."
Maybe there are elements of writing you get better at with practice -- the craft aspects, the ability to ride your unconscious like a bronco, that sort of thing -- and other elements where the five year hiatus would actually be a help? What might those other elements be? Unfortunately I suspect it'd be physically impossible for me not to think about writing for five years -- perhaps even for five hours -- so I may never find out...