Note:  Do not rely on this information. It is very old.

Mass

Mass. The celebration of the Lord's Supper, or Eucharist; it is generally used of the celebration in the Roman Catholic church. In music, a setting Ľof such portions of the Latin liturgy of the Eucharist as are adapted for musical performance, including the Kyrie, the Gloria, the Credo, the Sanctus, the Benedictus, and the Agnus Bei. [Requiem.]