Of the sacred works that Mozart composed in Salzburg none is as well known or as popular as the Mass in C K. 317. In 1779 Mozart returned from his disastrous trip to Paris and, partly out of material necessity and also to please his father, he took up a position in the Archbishop’s service in Salzburg. He was to “unbegrudgingly and with great diligence discharge his duties both in the cathedral and at court and in the chapel house, and as occasion presents, to provide the court and church with new compositions of his own creation”. At the first opportunity Mozart fulfilled this demand, composing the mass for the Easter Day service on 4th April 1779.
The musical style of the piece corresponds to the hybrid form that was preferred by the Archbishop: its use of wind instruments suggests a “Solemn Mass”, and its length suggests a “Short Mass”. Mozart himself described his task in a letter: “Our church music is very different to that of Italy, all the more so since a mass with all its movements, even for the most solemn occasions when the sovereign himself reads the mass [e.g. Easter Day], must not last more than 3 quarters of an hour. One needs a special training for this kind type of composition, and it must also be a mass with all instruments – war trumpets, tympani etc.” It therefore had be a grand ceremonial setting, but the mass also needed to have a compact structure. Mozart therefore omits formal closing fugues for the Gloria and Credo, the Credo with its problematic, vast text is in a tight rondo form, and the Dona nobis pacem recalls the music of the Kyrie.
Even as early as the 19th Century the mass was already popularly referred to as the “Coronation Mass”. The nickname grew out of the misguided belief that Mozart had written the mass for Salzburg’s annual celebration of the anniversary of the crowning of the Shrine of the Virgin. The more likely explanation is that it was one of the works that was performed during the coronation festivities in Prague, either as early as August 1791 for Leopold II, or certainly for Leopold’s successor Francis I in August 1792. (There is a set of parts dating from 1792, and the same parts were probably used the year before.) It seems that Mozart must have seen the chance to be represented at the coronation festivities in 1791, not only with La clemenza di Tito, but also with a mass composition: he wrote from Prague requesting that the parts for his old Mass in C be sent to him there. He was held in very high regard in Prague: The Marriage of Figaro had been a smash hit there, and they had commissioned Don Giovanni. It seems likely therefore that the city would have taken on the mass as its own, and the nickname would have grown from there.
Certainly the music itself is celebratory in nature, and would have fitted a coronation or Easter Day service perfectly. The soloists are continually employed either as a quartet, in pairs or in solo lines that contrast with the larger forces of the choir. The most stunning examples are the central hushed section of the Credo, and later when the Hosanna section of the Benedictus is well under way, the quartet begins the piece again, seemingly in the wrong place! Perhaps the most obvious reason for the mass’s popularity in Prague in 1791/2 was the uncanny similarity between the soprano solo Agnus Dei and the Countess’s aria Dove sono from Figaro which had been so successful there in the 1780’s.