Did Mozart Compose his Last 3 Symphonies in 6 Weeks?
It has been written and repeated so many times that Mozart composed his last 3 symphonies within a period of 6 weeks, that it has become ingrained in our minds. But the symphonies certainly were written over a longer span.
Mozart entered the works in this work catalogue on June 26 (K543), July 25 (K550) and August 10 (K551), 1788. Thus six weeks.
But these are the completion dates. Obviously at least K543 had to be started before this date. When we do not know. H.C.R. Landon in his 1957 volume for the NMA (and repeated in the Bärenreiter Study Score of 1988) stated ""from the preceding entry...it may be estimated that the Symphony was written down within four or five days". But is it really likely Mozart composed this symphony in 4 days? In a very simple (or realistic?) view if there is a month between the entry for K543 and K550 and 17 days between K550 and K551, this would mean the symphony K543 perhaps was started at least 17 days before its completion date and maybe a month--if we go by the completion dates of the following symphonies. That would add over two weeks or a month to the six weeks. Still impressive, but perhaps a little less Herculean. Recent commentators have expanded the time frame even more than my 8 to 10 weeks. Neal Zaslaw wrote they were "completed in the space of about three months"
Another factor is the June 26, 1788 entry of Mozart's for the 39th Symphony. Also entered on this date are a lost March K544, the Piano Sonata K545 and the Adagio and Fugue for String Quartet K546. Obviously we have a batch entry here. The entry prior to K543 is the Piano Trio K542, entered June 22. If we take Landon's 4 or 5 days serious, that means Mozart wrote the Symphony, the March, the Piano Sonata and String piece all in four days. Perhaps in these four days we can assume the finishing touches were put on some if not all these works. But surely the entire composition of these works would not have taken place in this short 4 day span.
David Wyn Jones offered up this hypothesis on when the symphonies were started. Alan Tyson's paper studies show the paper used by Mozart in the symphonies was used by him exclusively between December 1787 and February 1789. On December 19, 1787, the Wiener Zeitung announced the publication by Artaria of Haydn's six "Paris Symphonies" in two sets of three. The first, as Op.51, included the Symphonies in C, g-minor and Eb. Certainly these are the same keys as Mozart's last three symphonies. David Wyn Jones lists several points in the two composer's symphonies he finds point to Haydn's influence in Mozart's works that I will not go into here. The point is it is possible the Mozart symphonies were written as a response to this Artaria publication, and could have been started sometime after December 19, 1787, and finished in the summer of 1788. If this is the case we are talking about a much longer time span for the composing of the three symphonies.
Certainly Mozart was capable of knocking out works fast; but just because he was capable it does not necessarily follow that he did. I think it is safe to put the "6 weeks" statement for the composing of his last three symphonies in the back of the drawer.
As a note, Mozart's 6 weeks span has always been given to show Mozart could compose at a quick rate. However he was not the only composer who could compose symphonies in a short span. Michael Haydn completed 6 symphonies in a 7 week period in the same year 1788:
Symphony in Eb (P.26, MH 473) dated January 2, 1788
Symphony in G (P.27, MH 474) dated January 13, 1788
Symphony in Bb (P.28, MH 475) dated January 22, 1788
Symphony in D (P.29, MH 476) dated January 30, 1788
Symphony in F (P.30, MH 477) dated February 10, 1788
Symphony in C (P.31, MH 478) dated February 19, 1788
That Haydn's works are not the masterpieces that Mozart's are is not to be questioned, but nevertheless they were written in a very short time span. Masterpiece or not, the notes had to be put on paper.