Heinrich Keilholz

Sound and acoustic engineer. Born 21. Dezember 1908, in Hannover; died 21. April 1981, in Salzburg, Austria.
Worked for Deutsche Grammophon in the 1960s. His DGG recordings can be identified by a K or KE (usually followed by other letters, e.g. ◇Z).
Then followed a career as renowned acoustic engineer, refitting opera and concert houses in, e.g. Vienna, Stockholm, Salzburg.