Don Giovanni (referred to in this report as “das steinerne Gastmahl”, cf. Dokumente, 263) had its premiere in Prague on 29 Oct 1787. Mozart and Constanze had traveled to Prague early in October for the preparations and premiere, and they had returned to Vienna around the middle of November, just shortly before this report was published.
Le nozze di Figaro had premiered in Vienna on 1 May 1786, and had been performed eight times by the premiere of Martín y Soler’s Una cosa rara in Vienna on 17 Nov 1786. The tremendous popularity of Martín’s opera in Vienna seems to have overshadowed Figaro; at any rate, Figaro was given only once more, on 18 Dec, before the end of the run. (It was revived in Vienna with alterations at the end of Aug 1789.) Figaro was first performed in Prague in Dec 1786 and had been a huge success there; it was also performed in Oct 1787 in the weeks preceding the premiere of Don Giovanni.
The author of this report implies that Martín was in the process of writing a “Gegenstück” (counterpart) to Figaro for Prague, with the implication that Martín intended it to compete with Figaro’s success. The reference is probably to L’arbore di Diana, although Martín had, in fact, already completed that opera, which had its premiere in Vienna on 1 Oct 1787, before Mozart left for Prague. By the time of the Viennese premiere of L’arbore di Diana, Martín had already been appointed Kapellmeister to the Russian court, and he composed no more operas for Vienna.
The report states that Mozart’s friends were urging him to have Don Giovanni performed in Vienna, with the implication that its presumptive success there would counteract Martín’s attempt to outshine Mozart in Prague. Don Giovanni was first performed in Vienna (with significant alterations from the Prague version) on 7 May 1788, and was given 15 times in the first run. L’arbore di Diana was in the repertoire of the court opera in Vienna nearly continually from its premiere until 3 Mar 1791. Martín's opera reached Prague in 1788, with the Oberpostamtszeitung reporting that the lavishness of the Guardasoni troupe's costumes and sets ensured a performance of the opera on 16 January was an "unqualified success" (Berkovec 1989, 68.)
In spite of its shaky chronology, the report above does offer insight into the rumors and intrigue surrounding the business of new opera productions in both Vienna and Prague.