Originally, Gregorian was conceived as a more pop-oriented group in the vein of Enigma, the multi-million selling act created by Frank Peterson and Michael Cretu in 1989. In 1998, Peterson and his team Jan-Eric Kohrs, Michael Soltau and Carsten Heusmann re-invented the project to perform popular songs in the Gregorian style. The criteria for song selection were strict; in order to be considered, a song needed to be translatable into the 7-tone scale. For each album, songs were carefully chosen in addition to original songs written by Jan-Eric Kohrs, Amelia Brightman and Carsten Heussman. Twelve vocalists - previously acclaimed session and choir singers - were then hired to record the tracks.
Each Gregorian album is initially digitally tracked at Nemo Studios, Peterson's Hamburg studio. The vocalists then record their parts in a church atmosphere with dimmed lights and candles, in order to escape what Peterson referred to in a 2001 interview as the "cold and technical" studio atmosphere.
The concept proved to be successful, and the group proceeded to record several more Masters of Chant albums in the same style, and have been successfully touring throughout Europe and Asia for over 10 years.
Their album, The Dark Side of Chant, was released on 15 October 2010 in Europe and is now available for sale in the United States.