Complex sentence: After serving during World War II, he completed his apprenticeship at the Curtis, and in 1949 won the Naumburg award and made his recital debut in New York in November that year.
Split into simpler sentences: After serving during World War II, he completed his apprenticeship at the Curtis. In 1949, he won the Naumburg award and made his recital debut in New York in November of that year.