With his 'mahogany-toned voice and magnetic stage presence' (Opera Brittannia), Quirijn de Lang's list of more than 70 roles range from the famous Mozart baritone roles, such as the Count Le Nozze di Figaro, Don Giovanni, Papageno Die Zauberflöte, Guglielmo and Don Alfonso Così fan tutte, to Hamlet by Thomas, Zurga Les Pêcheurs de perles, Escamillo Carmen, Germont La Traviata, Ford Falstaff, Filippo Beatrice di Tenda, Malatesta Don Pasquale, Figaro Il Barbiere di Siviglia, Dandini La Cenerentola, Yeletsky Pique Dame, Pantalon Les Amours des trois oranges, Harlekin Ariadne auf Naxos, Ottokar Der Freischütz, and many more.
 In contemporary opera, highlights include: Oppenheimer Dr. Atomic, Lieutenant Audebert Silent Night, Almaviva Figaro gets a Divorce, Sam Trouble in Tahiti, and Pete Dayton Lost Highway.
 Quirijn de Lang is one of the few performers who crosses effortlessly between the genres of opera and musical theatre. He created the role of Jan Six Rembrandt, the Musical, and garnered much acclaim as Fred Graham Kiss Me, Kate and Fredrik Egerman A Little Night Music. Displaying much affinity with Kurt Weill's work, he performed Randy Curtis Lady in the Dark, Harry Easter Street Scene, and Moritatensänger Die Dreigroschenoper.
In 2025, he recorded the role of Samuel Cooper in the first full production recording of Weill's Love Life. 
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