found: Bulgarian Wikipedia, February 15, 2023:Ansambŭl za narodni pesni na Bŭlgarskoto radio (Ansambŭl za narodni pesni na Bŭlgarskoto radio; founded in Sofia in 1952; was made up of a choir and an orchestra of Bulgarian folk instruments) Orkestŭr za narodna muzika na BNR (Orkestŭr za narodna muzika na Bŭlgarskoto nat︠s︡ionalno radio; founded in 1952 as part of the then-Ansambŭl za narodni pesni na Bŭlgarskoto radio [ANPBR; Bulgarian National Radio Folk Song Ensemble]; in 1990, ANPBR ceased to exist when its choir was transferred to Bulgarian National Television and eventually took the name Misterii︠a︡ta na bŭlgarskite glasove; for its part, the ANPBR Orchestra stayed with Bulgarian National Radio and became the Orkestŭr za narodna muzika na Bŭlgarskoto nat︠s︡ionalno radio) Misterii︠a︡ta na bŭlgarskite glasove (after the commercial success in the late 1980s in Western countries of a series of four compilations of Bulgarian choral folk music released under the name Le mystère des voix bulgares (in Bulgarian: Misterii︠a︡ta na bŭlgarskite glasove), the former ANPBR women's chorus eventually took the name Misterii︠a︡ta na bŭlgarskite glasove)
