From the late 19th century Missa brevis (or French: "Messe brève") may refer to a Mass composition with any combination of the following characteristics: (1) short execution time, (2) limited forces for performance, (3) leaving out part of the Mass ordinary and/or (4) the composition is incomplete so that the extant complete parts are seen as a Missa brevis. A Mass being short in this sense does however not exclude that sections based on texts outside the Mass ordinary are added to the composition (like the O Salutaris Hostia in several of Gounod's Messes brèves).
