Slovenian bass Julij Betetto (1885–1963) undoubtedly left a deep mark on Croatian opera and concert performance in the first half of the 20th century. A cosmopolitan, but a patriot by heart, he interpreted around 175 roles in 140 operas and participated in more than 173 concerts. In total, he gave more than 3241 performances, from which more than 60 took place on Croatian opera and concert stages. The article deals with his important contribution in the artistic field as well as indirectly in the pedagogical field – many of his students successfully enriched the 20th-century Croatian operatic scene with their roles. The article looks at a selection of Betetto’s opera and concert performances in Croatia and their critical responses, pointing out also some of his Slovenian students who famously characterized the Croatian opera scene in the 20th century, including bass Marjan Rus and tenors Rudolf Francl and Josip Gostič.