Born near Alexanderplatz in Berlin to a middle-class Jewish family, Bruno Schlesinger began his musical education at the Stern Conservatory at the age of eight, making his first public appearance as a pianist when he was nine. However, following visits to one of Hans von Bülow's concerts in 1889 and to Bayreuth in 1891, he changed his mind and decided upon a conducting career. He made his conducting début at the Cologne Opera with Albert Lortzing's Der Waffenschmied in 1894. Later that year he left for the Hamburg Opera to work as a chorus director. There he first met and worked with Gustav Mahler, whom he idolized and with whose music he later became strongly identified.