Domagoj Ugrin is a Croatian violist. In recent seasons, he has been active primarily as a member of the Croatian Radiotelevision Symphony Orchestra, where he continues to perform across a wide symphonic, operatic, and ballet repertoire. He has been a permanent member of the Radiotelevision Orchestra since 2008.

After initially joining the orchestra as a violinist, he transitioned to the viola section, where he has since focused his artistic work. Ugrin is also a regular collaborator with ensembles such as the Croatian Chamber Orchestra, the Zagreb Chamber Orchestra, and the Dugo Selo Chamber Orchestra. He has also spent extensive time performing with the orchestra of the Croatian National Theatre in Zagreb, gaining broad experience in opera and ballet repertoire

He is a member of the Serena String Quartet, with which he has performed both in Croatia and internationally, valuing the quartet setting as a space for detailed musical dialogue and long-term collaboration.

Ugrin completed his violin studies at the Music Academy in Zagreb firstly with Vinko Fabris and then with Marija Ćepulić. He later completed his studies in viola with Krešimir Petar Pustički, formalizing his transition to the instrument that now forms the core of his professional work.

Mario Ivelja is a Croatian double bassist whose artistic life has been shaped by a deep dedication to chamber music, orchestral tradition, and the expressive potential of his instrument. Earlier in his career, he served as principal double bass of the Zagreb Philharmonic before joining the Zagreb Soloists in 1979, remaining with the ensemble for 43 years. Parallel to his performing career, he remained deeply engaged in teaching and mentorship, serving as a full professor with tenure at the Music Academy in Zagreb, where he educated generations of young double bassists before retiring.

For more than four decades, Ivelja was a core member of the Zagreb Soloists, one of Croatia’s most distinguished chamber ensembles, with whom he toured extensively around the world. His performances took him to major concert halls such as the Musikverein in Vienna, Carnegie Hall in New York, Teatro Real in Madrid, Salle Pleyel in Paris, the Mozarteum in Salzburg, and the Royal Albert Hall in London, as well as to leading international festivals including Salzburg, Bergen, and Prague Spring. Throughout his career, he collaborated with artists of international renown, among them Henryk Szeryng, James Galway, Jean-Pierre Rampal, Emmanuel Pahud, Steven Isserlis, Ilya Gringolts, and Igor Moretti.

Alongside his chamber music work, Ivelja has appeared as a soloist with renowned ensembles and orchestras in Europe and the United States. In addition to the standard double bass repertoire, he has shown a strong commitment to presenting works by Croatian composers such as Boris Papandopulo, Milko Kelemen, Anđelko Klobučar, and Dubravko Palanović, contributing significantly to the visibility of Croatian contemporary and classical music.