Music Biennale Zagreb is Croatia's flagship festival for contemporary music and one of the flagship projects of the Croatian Composers' Society (HDS), founded in 1961 by composer Milko Kelemen. Over more than six decades, MBZ has grown into one of Croatia's most internationally recognised cultural events, presenting symphony orchestras, chamber ensembles, contemporary opera, electronic music, multimedia installations, and contemporary dance. Throughout its history, MBZ has collaborated with figures including Luciano Berio, John Cage, and Witold Lutosławski. HDS is a professional association representing Croatian composers and music authors.