The program page below deserves a 'wanted' poster.
It features Furtwängler conducting the Nuremberg 'Philharmonischer Verein' orchestra for a concert on April 7, 1922.
– This concert is not listed among all known performances by Furtwängler.;
– It would be his only appearance as conductor of this orchestra;
– This would have been the only time he conducted the 3rd Symphony ('Västkustbilder') by Swedish composer Kurt Atterberg.
It is true that Furtwängler was 'available' at this precise period (April 1 in Vienna, April 16 in Rome), during which he was appointed in Berlin and Leipzig as Nikisch's successor. But there is no trace of this concert in his letters, nor in the newspapers of the time.
Disturbing are the notes written with blue ink: 'Vertreter' — 'Schuricht' — 'Wiesbaden'.
Could he have replaced Carl Schuricht? Or vice versa? But nothing about that date is mentioned in his eminent colleague's concert schedule either. That said, it is certain that Schuricht conducted Atterberg's symphony in his Wiesbaden stronghold in late 1921/early 1922...
It should be noted that the two local orchestras — of the Theater and of the Philharmonic Association —, that year merged to become the Nuremberg Philharmonic Orchestra. No doubt this is the origin of the 'vereinigten Orchester', reunited orchestra, which is mentioned on the document.
The hunt is on...