One of the most successful pop/classical fusion projects, Gregorian mixes well-known pop and rock songs with Gregorian chants. Overseen by producer Frank Peterson, co-founder of Michael Cretu's Enigma outfit, Gregorian's first album, Masters of Chant, released in 1999 (an early 1991 Peterson album released under the name Gregorian isn't counted among the group's official releases, but already employs the same aesthetic), became a smash hit throughout Europe, entering the Top Ten in nine different countries. The following albums continued in the same vein, covering songs by Peter Gabriel, Lenny Kravitz, Coldplay, Björk, Queen, Tears for Fears, and others. The Dark Side, released in 2004, put a stronger emphasis on the rock element and included songs by Nine Inch Nails and the Doors. Including two live DVD releases, several sequels to the Masters of Chant album, and a 2006 Christmas album, Gregorian sold over four million records under Peterson's guidance. ~ Christian Genzel