[2] He studied solo singing with Horiana Brănișteanu [de] and lied and oratorio with Wolfgang Holzmair at the Mozarteum University Salzburg.
[3] He also attended a number of master classes, including with Sir Thomas Allen, Brigitte Fassbaender, Marjana Lipovsek and Olaf Bär.
[17] Schuen sang the title role in Don Giovanni at the Opéra National de Montpellier in June 2013 and Guglielmo in Così fan tutte in December of the same year.
[19][20] In 2023, Schuen appeared as Wolfram in Wagner's Tannhäuser at Berlin State Opera[21] and as Count Almaviva in Mozart's Le nozze di Figaro at Salzburg Festival.
[25] In 2009 he premiered Herbert Grassl [de]'s song cycle ... Bald ist mir nimmer kalt for voice and drums.