Composer and musicologist Stevan Stojanović Mokranjac is considered the founder of modern Serbian music. The Serbian composers of the first generation Petar Konjović, Stevan Hristić, and Miloje Milojević maintained the national expression and modernised the romanticism into the direction of impressionism. Other famous classical Serbian composers include Isidor Bajić, Stanislav Binički and Josif Marinković. There are three opera houses in Serbia: Opera of the National Theatre and Madlenianum Opera, both in Belgrade, and Opera of the Serbian National Theatre in Novi Sad. Four symphonic orchestra operate in the country: Belgrade Philharmonic Orchestra, Niš Symphony Orchestra, Novi Sad Philharmonic Orchestra and Symphonic Orchestra of Radio Television of Serbia. The Choir of Radio Television of Serbia is a leading vocal ensemble in the country. The BEMUS is one of the most prominent classical music festivals in the Southeastern Europe.