UNFINISHED: Tradition and Completion of Mozart’s C Minor Mass

Guest post by Uwe Wolf, Chief Editor of Carus-Verlag


What an amazing story! Mozart makes a vow to compose a mass after the successful birth of his first-born child. The performance is planned on the occasion of his first journey with his wife to Salzburg so he can introduce her to his family – both personally and musically, for Constanze is to sing one of the demanding soprano parts. But the baby, left behind with a wet-nurse in Vienna, then dies, and Mozart stops work on the composition – precisely at the Et incarnatus est, one of his most beautiful and heartfelt movements, dealing with the subject of the incarnation, i.e. birth. Too much of a coincidence? Probably.

But there is some truth in this touching, very personal story.  A letter from Mozart to his father in January 1783, the only document from the time of the composition of the Mass which refers to the vow, is anything but clear – and consequently any connection between the C Minor Mass and the birth of little Raimund Leopold is frequently questioned. But various later statements by Constanze Mozart (who survived her husband by more than 50 years) regularly repeat this story over a long period of time. There are frequent references to the fact that Mozart promised his wife he would compose a mass if the birth was successful.

It is also true that Mozart stopped work on the composition: only the first two sections of the Credo were composed, and even these were only notated as drafts. The draft of the Credo ends abruptly after the Et incarnatus est. The further sections of the Credo, such as the Agnus Dei and Dona nobis pacem, are completely missing; however, probably relevant sketches show that Mozart clearly initially planned to compose the remaining sections. It remains completely unknown why he then stopped work on the piece. Was it really connected with Raimund Leopold’s death? Did Mozart really commemorate the birth of his son in composing the Et incarnatus est – admittedly one of the composer’s most beautiful and warm movements? If this was true, ending the work at precisely this place after the news of his son’s death would be logical, but this remains speculation on rather thin grounds.

Shortly before the couple’s return to Vienna, the C Minor Mass was performed in Salzburg – probably on 26 October 1783 – the only performance during Mozart’s lifetime. The Kyrie, Gloria, and Sanctus were performed with the Hosanna and Benedictus, that is, all the fully-composed movements. Whether the missing sections of the Ordinary of the mass were replaced by compositions from other masses is not known; at any rate, combinations of movements from different masses were nothing unusual. But even the movements of the mass which were performed put all of Mozart’s previous sacred compositions in the shade. In scale, the mass is reminiscent of Johann Sebastians Bach’s B Minor Mass which Mozart may have become familiar with.

Constanze Mozart sang as soprano soloist at the performance of the C Minor Mass in Salzburg; this was reported by both Mozart’s sister Nannerl and Constanze herself in retrospect. Mozart had provided well for Constanze for her first appearance in his native city: the Solfeggio K. 393, no. 2, probably written in 1782 “per la mia cara Costanza”, corresponds with the opening of the Christe eleison in the C Minor Mass, and was therefore possibly written as preparation for this first solo in the mass.

Soon after this Salzburg performance in October 1783, Mozart probably gave up the idea of a complete mass composition. Maybe because the extensive setting of mass movements ran directly counter to the efforts of the Reform Catholicism of the day, meaning that Mozart had little hope for other opportunities where the C Minor Mass might be used. Although he did no further work on it, he drew on the mass as source material in 1785 for the annual charity concert of the Vienna Tonkünstler-Sozietät (Society of Musicians), producing Davide penitente (Penitent David) K. 469, a compilation of psalm texts in Italian translation. Eight of the ten movements of Davide are parodies on music from the Kyrie and Gloria of the C Minor Mass. These sections of the mass were incorporated in full in Davide. Mozart did not use the two Credo sections present in the draft, nor were the Sanctus with Hosanna and Benedictus included in Davide. There is a plausible explanation for the latter: sections of the autograph manuscript now missing for those movements were evidently no longer available at this time, two years after the first performance. And the most crucial item is missing – the main score of these movements. Only woodwind, brass and timpani score for the Sanctus and Hosanna survives: for movements scored for larger forces, the 12-stave manuscript paper used by Mozart does not have sufficient space, which explains why he notated additional parts in a second, so-called “overflow score” which could accommodate all the woodwind, brass and timpani parts as in the double chorus Qui tollis and the Sanctus and Hosanna. Indeed the additional score of the two movements allows us to draw conclusions about the choral scoring – the autograph main score with vocal parts and strings has, however, been lost and with it also the autograph manuscript of the Benedictus which required no additional score due to its small-scale scoring.

Whereas the composition can only partly be reconstructed from the autograph of the score, at least some complementing sections were passed on in the parts of the Salzburg performance in 1783, which remained in the possession of Mozart’s father Leopold in Salzburg. After Leopold’s death, Mozart’s sister Nannerl sent these, together with other parts for church music works from her father’s estate, to the “Holy Cross” collegiate church of the Augustinian canons in Leopold’s home city of Augsburg. The local choirmaster, Father Matthäus Fischer (1763–1840) first prepared scores, probably around 1800, of the two choral fugues Cum Sancto Spiritu and Hosanna, evidently to be able to perform these pieces, because he reduced the scoring, omitting viola, bassoons and timpani, and also reduced the double choir Hosanna fugue to four vocal parts. In this arrangement, the composition was adapted to match the scoring of other church music works by Mozart and his contemporaries. Fischer later expanded this score to include all the sections of the mass present in the parts, now almost without any further reduction of the forces. Unfortunately the original parts are now largely missing, but thanks to Fischer’s copy, we are familiar with the string and vocal parts of the Sanctus and Hosanna at least in part and also of the Benedictus; nothing of the Benedictus survives in Mozart’s hand.

Performers and scholars today are posed with a complicated situation surrounding the sources, as the C Minor Mass is fragmentary in several respects: there are movements which Mozart composed which only survive in fragmentary form (Sanctus, Hosanna); there are movements which Mozart wrote out but did not complete (Credo, Et incarnatus est), and finally sections of the mass which, apart from a few sketches, he did not compose at all (the remaining sections of the Credo, as well as the Agnus Dei and Dona nobis pacem). The latter is the smallest of these problems, because in modern-day performances in concerts the liturgical incompleteness is negligible. But if a conductor also wishes to perform these missing sections, a version with additionally-composed material must be used, such as the successful edition by Robert Levin (Carus 51.427). But even if we limit ourselves to the surviving sections, some consideration has to be given to the fragmentary sections. The story of this incomplete work remains unfinished.

Shop Mozart’s Mass in c minor edited by Robert Levin on Sheet Music Plus.


1 Response to “UNFINISHED: Tradition and Completion of Mozart’s C Minor Mass”

  1. 1 Read the following attached article and answer the following questions – Homework Cheg Trackback on February 27, 2021 at 2:01 am

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