When the Nazis invaded Hungary during World War II his family had to hide. Most of them were found and taken to Auschwitz where they died. In spite of the terrible situation István’s mother encouraged him to keep practising music. After the war he graduated from school and went to the Royal Academy of Music (now the Franz Liszt Academy of Music in Budapest, where he studied violin, piano, and composition. Zoltán Kodály was one of his teachers. He soon became interested in conducting, and learned a lot from Bruno Walter, and Otto Klemperer, then the director of the Budapest Opera.