Gregorian choir sings modern pop songs, arranged in the style of the chants sung by medieval monks. The first two GREGORIAN albums (1999/ 2000 and 2001), produced by Hamburg, Germany-based Peterson (Enigma, Sarah Brightman) became international bestsellers, selling one million units each and reaching gold status in a dozen countries including Germany, France, Australia, South Africa and Singapore. The Gregorian Masters of Chant are the only worldwide touring Gregorian Choir, having played venues ranging from theaters to arenas to landmark churches.