[T]he multilateral treaties, conventions and agreements of an economic or technical character enumerated below … shall alone be applied as between Germany and those of the Allied and Associated Powers party thereto:
. . . .
(22) Convention of November 16 and 19, 1885, regarding the establishment of a concert pitch.
Well, you don’t do that. You pick one frequency, in our case it was generally 442 Hz, and then you play the whole concert with that.
Re-tuning a piano can easily take an hour. And re-tuning an orchestra is just as well a multi-minute cacophonie. The audience would rather listen to a slightly too brilliant death march than that…