It does not take much to bring a hidden event to the surface.
A tiny piece of paper, for example, can be enough — a concert ticket — to reveal a concert of Furtwängler that figures neither in the Trémine list, nor even in his source for Berlin, the voluminous history of the Philharmonic written by Peter Muck.
On 24 January 1940, the Berliner Philharmoniker and their conductor gave a concert in Essen the day after an evening at The Hague (the facsimile of the programme can be found on the SWF site) and on the eve of the stopover in Cologne in the course of this tour.
We have added it to the concert list on our site, unfortunately without the details of the programme. Any info gratefully received...