I. For the orchestra in Mozart's Requiem
The instrumentation of the present version of the Mozart Requiem includes flutes, oboes and clarinets in addition to the basset horns in the woodwinds. Marguerre thus follows the presumption of Friedrich Blume, the first publisher of the encyclopedia MGG. Blume asserts the Mozart Requiem in its traditional form with Süßmayr's additions to be "dominated by the uniformity of a rigid body of instrumentation, which Mozart certainly did not intend" (1). Mozart himself orchestrated only the introit to completion, for the woodwinds he only notes the 7-bar introduction to the Recordare and 4 bars in the Confutatis (with bassoons and basset horns).
These are particular passages in which Mozart consciously deviated from the usual instrumentation, and they function to emphasize the character of the funeral mass. The three passages are all in the key of F major/D minor; the basic tonality of the basset horns. Mozart could be argued to have left the instrumentation of the more contrasting sections of the sequence (text interpretation and key), particularly in the second part of the work, for a later stage, because it is generally possible here to observe the usual method, i.e. to lead the first oboe (and possibly the first flute) with the soprano, the second oboe (and possibly flute) with the alto, etc.
Even if there was not enough room for all the instruments on the 12-lined sheet, Mozart could have notated the remaining ones (such as the timpani or trumpets, for example) on an additional short score, from the Kyrie or at least from the Dies Irae onwards, a procedure quite common in the 18th century, which Mozart also used in his (also unfinished) Mass in C minor, K. 427. Regarding the instrumentation of his Requiem, the issue is therefore less one of practicalities, and concerns far more the appropriate instrumental garment in which Mozart intended to clothe the individual passages of the work.
In the second half of the 18th century, traditionally certain keys were assigned to denote particular affects or moods - and at the same time the wind instruments, which as of yet barely possessed keys or valves, are preferably used in their basic tonality. The fact that the inexperienced Süßmayr has used the deep basset horns in F in the Sanctus in the remote key of D major as a soprano reinforcement, seems almost paradoxical in light of this background and cannot be attributed to any intention of Mozart’s. Robert Levin, who demonstrated clear agreement with Marguerre on this particular point, employs the clarinets in A major for the Sanctus in his 1991 version. This can only be considered a partial solution, since the inclusion of the clarinet in A as the upper part of a large and robust-sounding choral movement is not wholly consistent with conventions of the time.
The requiem's clear tonal scheme suggests that Mozart would have used the various woodwind groups to illustrate the various aspects of the death theme: not only the sorrowful aspect (in the Introit in d minor) or the expression of the plea for mercy (in the Recordare in F major with the basset horns in F), but also for the representation of the existential fear of man (in the Dies Irae in d minor with the octave flutes), for the praise of the Lord (in the Sanctus in the radiant D major with flutes and Oboes), for the expression of the yearning for heavenly love (in the Benedictus in B flat major with the soft sound of B clarinets) and finally for the attainment of clarity and peace (in the C major cadence in the Agnus Dei with the oboes).
Considering the high classical art of orchestration of Mozart and his contemporaries, it does not seem plausible that Mozart, at his creative peak, would have renounced the expression of yearning for the beautiful and bright in the tonal embodiment of the high wind instruments in favour of a would-be gloomy, romantic mood. As long as no philological evidence for the orchestration of the individual movements of the Mozart Requiem can be found, the issue thereof cannot be decided theoretically either in one direction or the other. In practice, however, for the first time in the history of the Requiem, the present version presents an alternative to the traditional, unusually dull sound - with a sophisticated orchestral composition, which can be considered typical of a work of this size and significance by Mozart and, above all, attempts to support his liturgically based, most important statement.
In a manner consciously rich in contrasts Mozart has twice followed a large choral movement (Turba chorus) in minor with a soloistically composed, calming or comforting movement in major, before finishing the first part of the work with the Lacrimosa in the tonic key D-minor. In the second part, for example through the sequence of two major keys and the inclusion of cantabile lines in the Sanctus-Benedictus complex, a heavenly bliss is conveyed, which gives the work, despite its gloomy context, an overall hopeful development and direction. Three years before his Requiem, on April 4th, 1787, Mozart wrote a letter to his terminally ill father, which seems to be a confession of his own personal beliefs, and may be understood as a tenet at the heart of Requiem:
"Since death is the true purpose of our lives, I've become so well acquainted with this true, best friend of man for a few years, that his image holds nothing terrifying me, but is rather quite reassuring and comforting! - And I thank my God that He has blessed me with the opportunity, as I am sure you understand, to perceive it as the key to our true bliss. - I never lie down to sleep without considering that I, young as I am, might not be here the next day. And none of those who know me will ever be able to say that I am sorrowful or sullen in dealing with them. - And for this bliss, I thank my Creator every day, and I wish it from the bottom of my heart for each of my fellow human beings."(2)
II. The problem in completing Mozart's Requiem *
It is well known that the Requiem by Mozart in the version by F. X. Süßmayr requires many improvements. However, since its creation there has been a conflict between the desire to change as little as possible in the historical document, thus preserving reverence to Mozart’s student Süßmayr, and the desire to ‘complete Mozart's last legacy in a form befitting his greatness.’ (3) One such attempt still deservedly recognized is the new version by Franz Beyer (4): Here the instrumentation is freed from the greatest inaccuracies (including false accidentals) of the young Süßmayr. In addition, Franz Beyer also uses many passages from the (incomplete) instrumentation of the sequence by Mozart's pupil Josef Eybler, which is considered by many to be more adept than Süßmayr's attempt.
However, Karl Marguerre found such work to improve the "uncertain" movements Lacrimosa, Sanctus, Benedictus and Agnus Dei, insufficient. After his careful analysis, it becomes clear that this part of Mozart's work requires not only improved instrumentation, but in some places the additional improvement of compositional technique, melody, voice guidance and text placement. Süssmayr’s contributions to Mozart's fragmentary sketch of the vocal setting in the mentioned movements are, to Marguerre, so troubling that the very essence of Mozart is displaced in certain passages. This concerns, for example, the aimless harmony in the Lacrimosa from bar 9 onwards with the unresolved Neapolitan chord in bar 11, the fortissimo beats of the trombones in the middle section of the Benedictus, and the violin figure leading to the recapitulation, which would be more appropriate to a Strauss waltz.
These passages drown out the delicate filigree of Mozart's draft, thereby altering the mood of the whole movement. Should one wish in the middle or bridge passages of the Benedictus to draw on passages from Mozart’s Requiem, bars 15-19 and bars 43-45 of Introitus offer themselves, as well as bars 4-7 of Domine Jesus. These passages, in combination with the Benedictus motif, fit in wonderfully and have the inestimable advantage that it is precisely in the movement in which the image of God's Messenger appears that only Mozart himself speaks.
From the 7th bar of the Sanctus and from the 9th bar of the Lacrimosa, the segments to be bridged are longer. Marguerre considers the incusion of a further Mozart quote, in part with voice exchange to avoid troubling reminiscences, appropriate in any case and preferable to an ambitious, newer composition attempt.
The outline of the Amen Fugue is elaborated upon by Robert D. Levin in his version of the Mozart Requiem for the end of the Lacrimosa. However, according to C. Wolff, due to Mozart's sheet counting, it is unlikely that the Amen Fugue would actually resound at the end of the sequence, as it would have required far more sheets than Mozart had intended for the Lacrimosa (6). However, even if the sketch had in fact been used by Mozart, the following applies: at this point, which is not essential for liturgical progress, the figure of the requiem as a work of art in the shape of a torso may well be recognizable.
A comparison clarifies the intention of the restoration work to be carried out: It would hardly be possible to supplement the missing arms on the torso of Venus de Milo with new marble. Rather, one would try to remedy the obvious mistakes of the first restoration attempts with the help of historical material, so that the beauty of this high work of art becomes even more clearly visible.
III. For the interpretation of the present version
Notes for the edition of Karl Marguerres version, for example, for the performance of ornaments or tempo signatures, etc, are taken from Karl Marguerre’s book: "Mozart's Chamber Music with Piano" (7), completed after his death by his daughter Charlotte Heath-Marguerre, as well as from a concert recording from 1971 with Marguerre’s own version of the Mozart Requiem under his direction. Marguerre always placed particular emphasis on the choice of a suitable tempo, guided by the context of the text and the cadence, the frequency of the harmony changes and the focal points per bar, and the supporting voices. In the Agnus Dei, for example, harmony changes and syllabic changes predominantly occur once per bar. Therefore, Marguerre replaces in the musical text of Agnus Dei the eighths in cello / bass (8), probably stereotypically recorded by Süßmayr, with an accompaniment based on the almost identically constructed style of bars 27 ff following the Kyrie in D-minor KV 341 from Mozart's last creative period, and accordingly interprets the Agnus Dei 1971 in a fluid tempo. In the Lacrimosa too, Marguerre aims for an improved word emphasis, in which only the primary syllables are emphasised, resulting in the perception that the 12/8 beat is merged in the one measure. Marguerre interprets the beginning of the Sanctus as fluid; In the draft of the Osanna Fugue of the Sanctus, however, Mozart notates the fastest note values in eighths. Right at the beginning of the theme, a syncope results in a second emphasis in the bar. This prompted Marguerre to choose a more moderate tempo in interpreting his own deliberately more detailed treatment of the magnificent fugue theme.
Karl Marguerre (1906-1979) was appointed Professor of Mathematics and Mechanics at the Technische Hochschule Darmstadt in 1947, and the Rector for the academic year 1966/67. For more than 30 years, he headed the university orchestra and the choir of the institute and gave lectures on cultural history and musicology as part of the "Studium Generale". He has earned lasting merit not only for teaching and research in the field of mechanics and vibration theory, but also continues to be appreciated as a Mozart researcher, and as the first and renowned publisher of an original text of the complete violin sonatas of Mozart by the publisher Universal Edition in Vienna and the Piano trios by Mozart at the publishing house CF Peters in Leipzig.
Dorothee Heath, granddaughter of Karl Marguerre, is a violinist in the symphony orchestra of the city of Münster. She subjected the additions to the instrumental parts to a critical practical test. In addition, since there are significant deviations in some places in Süßmayr's copy, she was guided in the revision of all original passages by Mozart's autograph (in facsimile).
The revised version was performed for the first time under the direction of Fabrizio Ventura on 26.11.2016 in the Apostelkirche Münster by the Concert Choir and the Symphony Orchestra of the city of Münster.
Dorothee Heath, Münster in July 2018
 Musik in Geschichte und Gegenwart (Music in History and the Present)
 „ ...beherrscht von der Uniformität eines starren Besetzungskörpers, den Mozart so sicher nicht gewollt hat.“
* The second chapter of the foreword is based on an extensive study of the Mozart Requiem by Karl Marguerre, which I compared with recent findings in Requiem research.
 Ernst Hess: Appendix 1: „Mozarts letztes Vermächtnis in eine ihm wirklich würdige Form zu bringen.“
 I refer to Marguerre's essay: ‘Mozart and Süßmayr’ (5)
 Carus Verlag, 1991