Complex sentence: Haas began his formal musical education at the age of 14, and studied composition at the Brno Conservatory from 1919 to 1921 under Jan Kunc and Vilém Petrželka.
Split into simpler sentences: Haas began his formal musical education there at the age of 14. He studied composition at the Brno Conservatory from 1919 to 1921 under Jan Kunc and Vilém Petrželka.