Complex sentence: His businessman father, Francis, and ex-concert pianist mother, Annette, wanted him to learn to work for what he earned, and so each summer he would buy a pony at auction, train it, and then sell it before school started.
Split into simpler sentences: His businessman father, Francis, and former concert pianist mother, Annette, wanted him to learn to work for what he earned. Each summer, he would buy a pony at an auction, train it, and then sell it before school started.