The musical setting of the Roman Catholic mass was the most important compositional genre of the Renaissance. The mass is the principal daily service of the Catholic Church. The mass has two main divisions. The Ordinary consists of those portions of the mass said every day. The Proper consists of those portions of the mass particular to specific days/celebrations in the liturgical calendar.
The High Mass is divided into two broad parts, the first consisting of the Introductory and Liturgy of the Word, and the second consisting of the Liturgy of the Eucharist. Initially, all six parts of the Ordinary of the High Mass—the Kyrie, Gloria, Credo, Sanctus, Agnus Dei, and Ite Missa Est—were set to music. The Ite Missa Est was subsequently removed from this list. A single melody, usually a plainchant, will typically underlie all five parts of a Renaissance musical mass. The Renaissance musical mass had medieval precedents. Guillaume de Machaut’s isorhythmic Mass of Notre Dame set the Ordinary to music and tried to link melodically the diverse elements of the mass.
In a Cantus Firmus mass, the underlying plainchant is heard in its original, medieval form and usually in the tenor voice. This is the original and most archaic form of Renaissance mass.
In a Paraphrase mass, the underlying plainchant melody has been modernized according to the melodic tastes of the Renaissance. Josquin was the greatest composer of these masses.