All of my husband’s five children gravitated to music although he knows no one else in either his family or his ex-wife’s family who were musical. His children played in the school band, and his son can play, although he rarely does anymore, several instruments by ear.
Of course, Ben and his ex grew up poor in Argentina. Who knows what family members would have been musicians, or writers or artists, if presented with the chance? When working to survive occupies your time there is little room or energy for the things of passion.