copy, and after completion published
it; and in a letter to the publishers set up a claim to the
instrumentation of the "Requiem," "Kyrie," "Dies Irae," and "Domine," and
to the whole of the "Sanctus," "Benedictus," and "Agnus Dei." The
publication of Suessmayer's letter provoked a controversy which has raged
from that day to this. The ablest critics and musicians in Europe have
taken part in it. Nearly all of them have defended Mozart's authorship;
but after half a century's discussion it still remains in doubt how far
Suessmayer participated in the completion of the work as it now stands.
The bulk of the evidence, however, favors the theory that Suessmayer only
played the part of a skilful copyist, in writing out the figurings which
Mozart had indicated, carrying out ideas which had been suggested to him,
and writing parts from the sketches which the composer had made. One of
the most pertinent suggestions made in the course of this controversy is
that of Rockstro, who says:--

"Some passages, though they may perhaps strengthen Suessmayer's claim to
have filled in certain parts of the instrumentation, stand on a very
different ground to those which concern the composition of whole
movements. The 'Lacrymosa' is quite certainly one of the most beautiful
movements in the whole 'Requiem'--and Mozart is credited with having
only finished the first eight bars of it! Yet it is impossible to study
this movement carefully without arriving at Professor Macfarren's
conclusion that 'the whole was the work of one mind, which mind was
Mozart's.' Suessmayer may have written it out, perhaps; but it must have
been from the recollection of what Mozart had played or sung to him,
for we know that this very movement occupied the dying composer's
attention almost to the last moment of his life. In like manner Mozart
may have left no _Urschriften_ (sketches) of the 'Sanctus,'
'Benedictus,' and 'Agnus Dei,'--though the fact that they have never
been discovered does not prove that they never existed,--and yet he may
have played and sung these movements often enough to have given
Suessmayer a very clear idea of what he intended to write. We must
either believe that he did this, or that Suessmayer was as great a
genius as he; for not one of Mozart's acknowledged masses will bear
comparison with the 'Requiem,' either as a work of art or the
expression of a devout religious feeling. In this respect it sta