Complex sentence: By the time he was fifteen living in Okinawa, he already had his own band, called the "Cool Notes", and his own weekly TV show, an Okinawan version of "American Bandstand".
Split into simpler sentences: By the time he was fifteen living in Okinawa, he already had his own band, called the "Cool Notes". Not only did Sam have his own band at age fifteen, but he also had his own weekly TV show, an Okinawan version of "American Bandstand".