 Isidora Žebeljan got commissions from important institutions and festivals such as the Venice Biennale (The Horses of Saint Mark, illumination for orchestra, 2004), Bregenz Festival (opera The Marathon; Hum away, hum away, Stings for orchestra), Genesis Foundation from London (for the opening of Bill Viola's exhibition 'The Passion' at the National Gallery in London in 2003), University of Kent, Muziektheater im Revier Gelsenkirchen (opera Simon the Chosen), International Horn Society, Accademia Musicale Chigiana Sienna (opera Two Heads and a Girl), City of London Festival etc.She composed works for excellent musical ensembles such as Wiener Symphoniker, The Academy of St. Martin in the Fields, Brodsky Quartet, Berlin Philharmonic Octet, Dutch Chamber Choir and London Brass.Her compositions were regularly performed in whole Europe, Israel, USA and Asia including the festivals Venice Biennale, Bregenz Festival, Festival RAI Nuova Musica, City of London Festival, ISCM Festivals (Gothenburg, Wrocław), Festival Classique The Hague, Galway Arts Festival, Tallinn Summer Music Festival, WDR-Musikfest, Settembre musica Milano-Torino, Ultima Festival (Oslo), City of London Festival, Swaledale Festival, Walled City Music Festival, Dulwich Music Festival (UK), Eilat Festival (Jerusalem), Festival Nous Sons (Barcelona), Festival L' Est (Milano), Crossing Border Festival (The Netherlands), Settimana Musicale Senese, Musical Biennale Zagreb, BEMUS (Belgrade), etc.