When Bauhaus singer Peter Murphy played Ivo an unlabelled tape of a Bulgarian women's choir that he'd been given by an acquaintance, 4AD's founder was stunned by the power of their voices and embarked upon a frantic quest to learn more about them. It transpired that the tape in question was titled Le Mystere Des Voix Bulgares [The Mystery Of The Bulgarian Voices], and that it consisted of field recordings made over a 15-year period by ethnomusicologist Marcel Cellier. Ivo decided to license the recordings, and the resulting 4AD album proved massively popular. The label's first release of 1988 was a second volume of Le Mystere Des Voix Bulgares featuring a further 18 performances drawn from the Cellier archive.