Stieber attended grammar school in Halle an der Saale, where his father last worked as 1st director of the North German Knappschaft [de]s pension fund.
His great-grandmother was the Berlin court actress Friederike Komitsch, née Schaffner, who was married in her first marriage to the famous actor Ludwig Devrient.
His grandfather Wilhelm Stieber, a lawyer and criminologist, served as head of the Central-Nachrichten-Bureaus at the Preußisches Staatsministerium [de] in Berlin.
His repertoire included Belmonte from Die Entführung aus dem Serail (Mozart), Nureddin from Der Barbier von Bagdad (Cornelius), Fritz from Der ferne Klang (Schreker), Alviano from Die Gezeichneten (Schreker), Mephisto from Doktor Faust (Busoni), Duke from Rigoletto (Verdi), Alfredo from La Traviata and Klas from Enoch Arden [de] (Gerster).
According to Devrient's diary, published posthumously in 1975, he was supposed to provide relief after Hitler was diagnosed with impending vocal cord paralysis due to overexertion.
Devrient not only trained Hitler's voice and speaking technique, but also improved his presence as a political speaker in front of large audiences through acting and rhetoric lessons.
In order not to undermine Hitler's credibility or even expose him publicly to the ridicule of his opponents, Devrient had to work under the utmost secrecy.
In the cinema comedy My Führer – The Really Truest Truth about Adolf Hitler (2006), director and writer Dani Levy has the German dictator taught by a Jewish concentration camp prisoner.