Le Mystère Des Voix Bulgares has been played over 40 times on NTS, first on 18 November 2012. Le Mystère Des Voix Bulgares's music has been featured on 39 episodes.

Le Mystère des Voix Bulgares (aka Les Voix Bulgares, The Mystery of Bulgarian Voices, Voix Bulgares - plus, formerly, Bulgarian State Radio and Television Female Vocal Choir & Bulgarian State Television Female Vocal Choir, Мистерията на българските гласове), is an all-female choir, formed in 1952. This naming is taken from the title of 1975 record, produced by Marcel Cellier - "Le Mystère des Voix Bulgares, Volume 1" - in which they featured, along with other Bulgarian folk choirs / soloists, including Trio Bulgarka, Yanka Rupkina, Kalinka Valcheva and Stefka Sabotinova. Their music is based on over a thousand years of musical tradition of Bulgaria, arranged by Bulgarian composers from the 1950s to this day. Their resonant and vibrato-free vocal quality is unique to Bulgaria. Most of the singers are originally from the rural regions of the country trained in their regional singing styles. They are currently directed by Bulgarian conductor Dora Hristova.

Their initial commercial release was in 1966 with the album “Music of Bulgaria” on the Elektra label. Seven albums followed during the late 80s and 90s, including one live album “A Cathedral Concert” in 1988 and a remix album “From Bulgaria With Love” in 1993. To-date their last release was in 2001.

In the UK, their reputation was secured by the re-release of "Le Mystère des Voix Bulgares, Volume 1" on the 4AD label.