Complex sentence: Pedreira was born into a family that formed part of San Juan's "High Society" who sent him to the best known private schools on the island and from a young age gave him private music lessons.
Split into simpler sentences: Pedreira was born in San Juan, Puerto Rico, into a family that belonged to San Juan's "High Society". The family sent him to the best private schools on the island at the time and at a young age had him take private music lessons.