The very dramatic and visually compelling film Amadeus does certainly have a lot to answer for in the realm of fact but of one thing in which it is correct in is that this music is very powerful and emotionally engaging. This is a somewhat curious fact that not only was it unfinished by the genius of Mozart but large parts of it were in fact written by another composer of inferior ability* (which of course begs the question what would the final Requiem have sounded like if Mozart had lived to complete it himself?).
Current convention states that when Mozart died he himself had completed (?) the opening movements of the Requiem i.e. the Introit and the Kyrie. The next eight sections had full vocal lines, figured basso continuo and outline sketches for orchestration. The final sections of the Sanctus, Benedictus, Agnus Dei and the Communio were apparently composed by Sussmayer who also “completed” the orchestration that was missing in the other sections. Debate and controversy regarding exactly what Mozart did and did not write still continues and adds to the mystery and romantic appeal of this work. That is one of the very many charms of the romanticism surrounding the work for me; that “what if” factor. I think that it is also curious that, to be fair to Sussmayer, considering all that has been written about him and his ability, his is still probably the version that is still most often heard.
In relation to period or modern instrument performance that is of course a very subjective thing and a matter of personal taste (and I have almost equal quantities of both approaches in my collection) but one fact in relation to the scoring stands out for me and that is that the scoring says something about what way the composer wanted the work to be heard; the music is spiritual, dramatic and atmospheric (possibly that of a young man terrified by the belief that he was going to die) and the scoring reflects that i.e. two basset horns, two bassoons, two trumpets and three trombones with timpani, strings and organ which give the work a dark, rich texture and which also lends to a “big” sounding performance statement.
It is a work that I have found particularly appealing ever since I first started listening to it many years ago.
*Anyone who has any question in this regard will get a very good indication of this when the two works of the respective men are very well compared on this CD....
