Born in Solingen, Hoelscher was the youngest of three children of a jeweller and amateur violinist, who wanted to form a family string quartet.
[2] Hoelscher was one of the most important musicians of the Nazi era, which is reflected in his inclusion in the Gottbegnadeten list, published in August 1944, which set him free him from military service.
In the same year, Hoelscher performed at the Beethoven Days of the Hitlerjugend in Wildbad and at the cultural-political work camp of the Reichsjugendführer in Weimar and played for the "Lichtfest" in front of the staff of four industrial companies.
[8] For the purpose of "cultural propaganda", he performed in 1942 in occupied Belgium at travelling concerts for the Wehrmacht in Antwerp, Ghent, Mechelen, Leuven, Lier and St. Niklaas.
[5][6]: 3138 Only a few months before the end of the war, on 2 December 1944, he performed in Krakow with the Philharmonie des Generalgouvernements, an orchestra of Polish players founded by Hans Frank for propaganda purposes.
[7][9] Despite membership in various Nazi organisations, besides the party also the Reichskolonialbund and the Nationalsozialistischer Altherrenbund [de],[5] Hoelscher could continue his career after the Second World War.
[8] He premiered over 50 works, including compositions by Wolfgang Fortner, Hans Werner Henze, Ernst Krenek, Pfitzner,[1] Günter Bialas, Harald Genzmer, Martin Karl Hasse, Karl Höller, Peter Jona Korn, Casimir von Pászthory, Joseph Rheinberger, Heinrich Sutermeister and Ermanno Wolf-Ferrari.