the most elite violinists accumulated about the same number of hours of deliberate practice (about 7,410 hours) by the age of 18 as professional middle-aged violinists belonging to international-level orchestras (about 7,336 hours)! By the age of 20, the most accomplished musicians estimated they spent over 10,000 hours in deliberate practice, which is 2,500 and 5,000 hours more than two less accomplished groups of expert musicians or 8,000 hours more than amateur pianist
