VR Prova: Requirements Analysis for a Collaborative Virtual Reality Opera Rehearsal Platform. - Emmanouil Xylakis; Konstantinos Tsamis; Charalampos Vatsolakis; Loukas Fatouros; Dionisia Mavria; Giorgos Gkanidis; Panagiota Dania; Vasiliki Geropanta; Anna Karagianni; Panos Parthenios (CHI Greece, 2025)