I have seen this time and again with other "musical geniuses" where their environment is so rich even if their own parents are not musicians. The hit musical "Hamilton" whose composer/writer is Lin-Manuel Miranda is a case in point. Lin-Manuel grew up with parents who were not musicians. However, his parents loved music, especially musicals. His parents played recordings of musicals all the time--at home, in the car. His parents owned over 100 records and Lin-Manuel recalls being immersed in music. He also had an older sister that loved rap, which he also loved. Just like Anthony, Lin-Manuel was bathed in music for most of his life and he got to see others around him enjoy music. It is not surprising that musicians of such caliber come from such musically rich environments.
I recently read a book by Dr. Benjamin Bloom called "Developing Talent in Young People" where it detailed a study of 120 people who are at the top of their professions like Olympic swimmers, tennis players and concert pianists. They probed into these people's childhoods and even asked their parents to give information about all sorts of things including the type of coaches or teachers they had growing up. What was noticeable about the concert pianists is that most of them were not seen as particularly gifted in music. What they all had in common was that their first piano teachers were all warm and caring. Thus, their first experiences with piano lessons were positive and fun. These first teachers were not concert pianists, but they knew how to teach children and they knew how to support and inspire these future concert pianists to love playing the piano. The parents also played a large role by being present for lessons and helping with consistent practicing at home. Thus, in a supportive and encouraging environment like these, the concert pianists were able to develop a passion for music while also learning that practicing can be fun but also a lot of hard work. Similarly, the coaches the top tennis players and swimmers first had tended not to be professionals but definitely kid-friendly, making lessons fun and positive and instilling in them a love of their sport.