Gregorian chant was traditionally sung by choirs of men and boys in churches, or by women and men of religious orders in their chapels. It is the music of the Roman Rite, performed in the Mass and the monastic Office.

Although Gregorian chant supplanted or marginalized the other indigenous plainchant traditions of the Christian West to become the official music of the Christian liturgy,

Although Gregorian chant is no longer obligatory, the Roman Catholic Church still officially considers it the music most suitable for worship.

During the late 20th century, Gregorian chant underwent a musicological and popular resurgence both within and outside the Roman Catholic Church.

The renewed interest in early music in the late 19th century left its mark on 20th-century music. Gregorian chant has been incorporated into other genres, such as Enigma's "Sadeness (Part I)", the chant interpretation of pop and rock by the German band Gregorian.

Gregorian is a German band, headed by Frank Peterson, which performs Gregorian chant-inspired versions of modern pop and rock songs. Because it features both vocal harmony and instrumental accompaniment, the music cannot be considered true Gregorian chant.

Originally, Gregorian was conceived as a more pop-oriented group in the vein of Enigma. Under this concept, they recorded the 1991 album Sadisfaction, with lead vocals provided by The Sisters of Oz: Susana Espelleta (Peterson's wife at the time) and Birgit Freud. However, this was the only album in that style.

In 1998, Peterson and his team 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. After the songs were chosen, twelve vocalists - previously acclaimed session and choir singers - were hired.

The members of the Gregorian choir group are Richard Naxton (Naxos), Johnny Clucas (Johnny), Dan Hoadley (Dan), Chris Tickner (Chris T.), Richard Collier (Rich), Gerry O'Beime (Gerry), Gunther Laudahn, Lawrence White (Lorro), Jan-Eric Kohrs and Rob Fardell (Rob F.).

Others who contribute to the vocals or sound of Gregorian are Sarah Brightman (under the pseudonym Hepsibah), Frank Peterson, Amelia Brightman, and staff of Nemo Studio among others.