Complex sentence: In 1951 he was awarded the Mendelssohn Scholarship, which enabled him to study with Goffredo Petrassi in Rome, where he met his first wife, Lydia Angela Vignapiano, by whom he had two children (Angela and Robert).
Split into simpler sentences: In 1951 he was awarded the Mendelssohn Scholarship, which enabled him to travel to Rome to study with Goffredo Petrassi. He met his first wife, Lydia Angela Vignapiano, in Rome in 1951, by whom he had two children (Angela and Robert).