Jean-Léon Klostermann performed the title role in Der Vetter aus Dingsda (De Nieuwe Nederlandse Operette), Geharnischter in Die Zauberflöte (Noord Nederlands Orkest, Jan Willem de Vriend, conductor), Trin in La Fanciulla del West  (debut at Zaterdag Matinee, Concertgebouw), the title roles in Alladin und die Wunderlampe  by Nino Rota (Vlaamse Opera Antwerp and Luxembourg), Don Chisciotte in Sierra Morena  by Conti  (Opera aan het IJ, Amsterdam), and Horace in La Colombe by Gounod (Grachtenfestival, Amsterdam), Taylor and Prince/Black Peter in Kwasi and Kwame by Jonathan Dove (Onafhankelijk Toneel, Rotterdam), Physignatus in Strauss' Des Esels Schatten  (Zaterdag Matinee, Concertgebouw Amsterdam, tv broadcasted by NPS).

Last season Jean-Léon Klostermann made his debut at De Nederlandse opera, performing Erscheinung eines Junglings in Die Frau ohne Schatten, sang Eisslinger in Die Meistersinger von Nürnberg (Zaterdag Matinee, Concertgebouw Amsterdam), Arcas and Mercure in Hippolyte et Aricie (Nationale Reisopera Enschede), St. Brioche in The Merry Widow (Het Gelders Orkest, Concertgebouw, Amsterdam), and Gernando in L'isola disabitata (Grachtenfestival Amsterdam).

More recently he has sung Third Jew in Salome,  Trin in La Fanciulla del West , Altoum in Turandot (all at De Nederlandse opera, Amsterdam), and the tenor arias in Bach's Matthäus Passion (Toonkunstkoor Amsterdam, Holland Symfonia, Concertgebouw Amsterdam).

Upcoming engagements include Benvolio in Roméo et Juliette, 1^er Gefangene in Fidelio (both at De Nederlandse Opera) and Messager in Saint-Saëns's Samson et Dalila (Zaterdag Matinee, Concertgebouw Amsterdam), among others.