Düsseldorf, Neanderkirche. Rieger 1965. A "modern" organ without compromizes, on which Almut Rössler (1932-2015, and organist at the nearby Johanneskirche) recorded the complete organ works of Olivier Messiaen, and Oskar Gottlieb Blarr (*1934) works by Bartok and Mussorgski (yessss, pictures at an exhibition).
The organ case is not exactly "beautiful", and is in stark contrast with the XVIIth century church, in typical calvinist arrangement : pulpit and altar at the long side, galleries on the three other sides. Musically, it is overwhelming and elegant at the same time, singing and percussive (also with the help of the four horizontal trumpet and clarion stops).
I have listened to its voice on records for more than forty years. Live on the 27th, for the first time.