Missa

The Missa K.257 bears the non-authentic dating 1776 and was presumably composed at the end of 1776 or in the first half of 1777. Like K.262 (246a), it is designated in Leopold Mozart’s handwriting as a Missa longa on the cover page of an early composite manuscript containing the five masses in C major. K.257 is listed there as the last work. The designation “Missa longa” was intended to point out that this was an extensive, full-scale mass. Normally, it would have been called a Missa solemnis but Mozart, for unknown reasons, did not make use of this customary nomenclature.

The name “Credo Mass” is taken from the acclamations of “Credo” that constantly interrupt thelike-named movement. The Mass is remarkable for its density of invention within the narrowest of confines. Further, its instrumental accompaniment has an almost chamber-music quality that emerges time and again into almost symphonic proportions.