Posterity has never really been satisfied with Süßmayr’s completion of Mozart’s Requiem, so that many other completions have been made. Now Michael Ostrzyga (b. 1975) has presented a new version. As conductor, composer and Music Director at the University of Cologne, Ostrzyga is someone with practical experience. But he is also a composer, trained and experienced in analysis, arranging, orchestrating and creating works in different styles. He has immersed himself long and intensively in Mozart’s musical language. In conversation, he told Christoph Schulte im Walde about his approach.

The task of completing Mozart’s fragmentary Requiem has already been attempted several times. Now you are publishing your own version. Why?

Ostrzyga: The music has always fascinated me, much more than the whole mystery surrounding its composition. Of course I know and have a high regard for earlier attempts. We stand on the shoulders of those who came before us. But the fact that I started a new version probably shows that previous attempts have not entirely convinced me.

What doesn’t convince you about them?

Well, let’s say, there is still untapped potential for a comparative approach towards Mozart’s musical texts. And also over the last decades, there has been a lot of progress in research. We know more about Mozart’s ways of working, but also more about compositional thinking in the 18th century. The older published completions are to a greater or lesser extent based on music-theoretical ideology, as indeed is the musicological commentary on the compositional contexts in the Requiem.

Looking at the musical texts – does that mean that other works by Mozart, especially his church music, give indications of how Mozart might have composed the missing parts of his Requiem?

We will never know exactly, and music is also always perceived subjectively. But not everything is a question of taste. The musical texts can be compared with one another. What occurs how and where, and how often? What doesn’t occur? But clearly, something which corresponds exactly with Mozart’s stylistic precepts can displease, and something which doesn’t correspond, or doesn’t wholly correspond, can please. The whole enterprise is actually a pipe dream. But some probabilities can be better demonstrated than others, and for me, Mozart’s musical texts have been decisive.

Was that not the case for earlier arrangers?

Yes, I think it was. But I think that some didn’t allow enough time for comprehensive consideration of the scores to identify diverse and continually recurring questions, but to make things simple, relied on generalised preconceptions or their stylistic intuition. Otherwise, it cannot be explained that, for example, a false relation in Süßmayr’s Sanctus was criticised as “coarse” and “un-Mozartian”, although Mozart wrote false relations, including precisely this one and many other similar ones, also in comparable places. Or that a Requiem completion contains more extreme notes in soprano and tenor than all of Mozart’s choral works taken together, which is an absurdly high concentration and ignores the fact that in Mozart, such extreme notes were not simply used without good reason, but were reserved for special situations.

Your experience as a choral conductor surely came in here?

Yes, something like that perhaps doesn’t occur to you if you’re not involved in the practicalities of vocal music. Many colleagues from the choral music world mention this tessitura problem in this questionable version when the subject of Requiem arrangements arises. In this case, the contrapuntal materials in the choral writing are simply chosen or layered in a way which is implausible for Mozart. Despite this, this version is one which is performed quite often.

Where do you still see problems with approximation?

A scholar claims that Süßmayr’s rhythm for “Domini” in the Benedictus is “wrong” and was never written by Mozart. If one believes this, would it not be sensible to check through all the musical texts for the word “Domini”? In the Spatzenmesse [Sparrow Mass] there is a movement in a comparable tempo, and here Mozart wrote this rhythm six times. Or: experts are of the opinion that Süßmayr’s Hosanna is far too short, as is the preceding section in the Sanctus. What would you do if you suspected this?

... draw on the corresponding movements by Mozart?

Precisely! For what could be easier to verify? It’s astonishing, but nobody has ever done this before. At least, I haven’t found any reference in the research literature. And this opinion about the Sanctus and Hosanna is very often heard. In the literature, the opinions of highly respected researchers are constantly repeated, as if these opinions constituted a fact or the truth.

Have you read the entire research literature?

That’s probably impossible: so much has been written about the Requiem! But I’ve tried. I’ve read a great deal.

Back to the Hosanna and Sanctus. Is it then too short in the Süßmayr version?

In Mozart we find similar short and even shorter movements of this kind, particularly in works which he performed or had lying on his desk in 1791, the year the Requiem fragment was written.

It strikes me that you are defending Süßmayr.

Much of Süßmayr’s work could not plausibly have been written by Mozart, or this can be ruled out. But his critics, particularly in the 20th century, frequently wrongly disparaged him because they did not know any better, but perhaps they should have known better. The Requiem brings out the best, but also the worst in people. A few years ago, a scholar compared the Requiem debate amongst musicologists to the film series “The Godfather”.

What was also important to you in your work?

Handel and Bach. The music in the fragment speaks volumes in this regard, but we also know from other sources that Mozart consciously and purposefully examined the music of Handel and Bach and allowed this to flow into the Requiem. Therefore I have drawn on those works by the two earlier composers that Mozart knew or might have known, and tried to determine how this material appears in the late works of Mozart. Specifically, for the Requiem, Mozart studied Handel’s Funeral Anthem for Queen Caroline. I have also studied this closely and attempted to find traces of it in the fragment, and not only in the Introitus, that’s old hat. And of course, Mozart arranged some Handel oratorios, so I have been able to compare the original and the arrangement. And he had a penchant for Bach’s fugues. I tried to imagine how this would have revealed itself in the Requiem.

(from “Musik & Kirche” 4/2023 and “[t]akte” 2023 / translation: Elizabeth Robinson)