Bulgarian State Radio & Television Female Vocal Choir

Formed in 1951 under the direction of Philip Koutev, and originally known as The Philip Koutev National Folk Ensemble they are best known for their contribution to the "Le Mystère Des Voix Bulgares" series of LPs released by Marcel Cellier from 1975 onwards.

Allegedly John Fryer played a cassette tape of Marcel Cellier's first volume of recordings to 4AD principal [a=Ivo] who decided to licence and reissue them. The result was "Le Mystère Des Voix Bulgares" an LP of recordings by the choir - who were, however, uncredited leading many to believe that Le Mystère Des Voix Bulgares was the name of the choir.

Volume 2 of the series featured recordings from the choir - credited as Choeur RTB - and other folk groups, as did Volume 3.

The success of the series encouraged the choir to tour, and a "super group" featuring members of the choir and other folk groups toured in the 1990s under the name "Le Mystère Des Voix Bulgares" or "The Mystery of Bulgarian Voices" under the leadership of Dora Hristova. This ensemble recorded the "Ritual" and "Bulgarian Custom Songs" and the live LPs "A Concert in the Cathedral" and "Melody Rhythm and Harmony."