The large-scale work, a missa solemnis, is scored for two soprano soloists, a tenor and a bass, double chorus and large orchestra.

In a letter to his father Leopold dated 4 January 1783, Mozart mentioned a vow he had made to write a mass when he would bring his then fiancée Constanze as his wife to Salzburg.

[2] Mozart had moved to Vienna in 1781, but was paying a visit to his home town in the company of Constanze, who had not yet met his father or his sister (Nannerl).

The orchestra consists of 1 flute (only used in the Et incarnatus est), 2 oboes, 2 bassoons, 2 horns, 2 trumpets, 3 trombones, timpani, organ, and strings.

The work embodies pomp and solemnity associated with the Salzburg traditions of the time, but it also anticipates the symphonic masses of Joseph Haydn in its solo-choral sharing.