Mass in C major, K. 262 "Missa longa"

The Missa longa in C major, K. 262/246a, is a mass composed by Wolfgang Amadeus Mozart in May 1776.^[1] Other sources claim it was composed in May 1775.^[2] It is scored for SATB soloists, SATB choir, violins I and II, 2 oboes, 2 horns in C, 2 clarini (high trumpets) in C, 3 trombones colla parte, timpani and basso continuo.

Missa longa in C major
Mass by W. A. Mozart
Salzburg Cathedral may have been the first performance venue of the mass.
Catalogue	K. 262/246a
Composed	1775 (1775): Salzburg
Movements	6
Vocal	SATB choir and soloists
Instrumental	orchestra continuo

The mass is classed as a missa longa due to its length. However, due to its lack of extended writing for the solo parts, it has also been categorised as a missa brevis.^[1] The occasion the mass was composed for remains debatable. It may have been composed at the Archbishop Colloredo's request for a special occasion at the Salzburg Cathedral, or at the directive of a different priest – Colloredo's preference for brief settings makes it unlikely that he would have approved of the missa longa.^{[2]: 387 [3]} Alternatively, it may have been composed for performance at St Peter's Church.^[1][2]

The mass is divided into six movements.

1. Kyrie Allegro, C major,
2. Gloria Allegro con spiritu, C major,

   "Qui tollis peccata mundi" Andante, G minor, ³
   ₄

   "Quoniam tu solus Sanctus" Allegro con spiritu, C major,

3. Credo Allegro, C major, ³
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   "Et incarnatus est" Adagio ma non troppo, C major,

   "Et resurrexit" Molto allegro, C major,

   "Et in Spiritum Sanctum Dominum" Allegro, G major, ³
   ₄

   "Et unam sanctam" Allegro, C major, ³
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   "Et expecto resurrectionem" Adagio, C major,

   "Et vitam venturi saeculi" Allegro, C major,

4. Sanctus Andantino, C major, ³
   ₄
5. Benedictus Andantino, F major, ³
   ₄
6. Agnus Dei Andante, C major,

   "Dona nobis pacem" Allegro, C major,