The Mass K.262 (246a) is known as Missa longa. Leopold Mozart designated it so next to the incipit on the cover of the autograph collection of five masses in C major by his son. Mozart literature gives the year of origin as 1776, without mentioning the speculative nature of this claim.
The monumentality of the Missa longa suggests that the work was written for a particularly solemn occasion. When scanning for outstanding ecclesiastical events in the 1770’s, one cannot ignore the consecration of Ignaz Josef Count Spaur, coadjutor and administrator of the diocese of Brixen, as titular bishop of Chrysopel on 17 November 1776 in the Salzburg cathedral. Erich Schenk claims that Leopold Mozart’s mention of Wolfgang’s “Spaur Mass” in a letter of 28 May 1778 was in reference to the consecration of Ignaz Josef Spaur, an old friend of the Mozart family. Mozart’s work would then have to be seen as an homage of a truly personal nature. The Missa longa is the only setting of the Ordinary from this period which is appropriate to such a highly solemn event.Urtext of the “New Mozart Edition” Ideal for church services and concert performances Full score & performance material (BA4853) and vocal score (BA4853-90) for sale