Barmbeck is a part of Hamburg, which seems to be written Barmbek these days. It seems unlikely that the building of the Realschule is still in existence, given the destruction of Hamburg during the Second World War. There is still an “Uferstrasse” which, as you would infer from the name, is on the banks of a canal that leads to the Alster, a tributary of the Elbe.
I’m wondering if the musicians named there were members of the church, or were just hired guns for the evening. The flyer says that in addition to the named artists, other “well-known artists” would be appearing. It definitely sounds like a good way to spend One Reichsmark!