Mass

The mass in the Middle Ages served as an essential core of the Roman Catholic Church, lasting as one of the primary sources of music of the past. By around 600 the individual portions of the Mass in addition to its fixed structure were instituted. The mass fits into the category of sacred music, i.e. compositions usually with religious themes and that are intended to be performed for religious occasions, like church services. The Last Supper serves as the final section of the mass. The Mass can be either spoken, called Low Mass, or sung, called High Mass.

The church divides its prayers into two separate categories: the Proper and the Ordinary.

In the Ordinary, consisting of five parts, the lyrics never change throughout the whole year. The five sections, usually sung in plainchant, are listed in the following: Kyrie (eleison), Gloria (Gloria in excelsis Deo), Credo, Sanctus, and Agnus Dei.

The texts of the Proper part of the mass, however, are altered throughout the year based on Church holy days, such as Easter and Christmas. The following represents the parts of the Proper part of the mass: Introit (between Kyrie and Gloria), Gradual, Alleluia Sequence (succeeded by Credo), Offertory (succeeded by Sanctus Benedictus and Agnus Dei), and Communion (followed by Ita missa est.)

The Haec Dies chant is an example of the Gradual in the Mass Proper sung at Easter Sunday service. Masses were even composed in the Renaissance, specifically by Palestrina.