[2][3] In 2004, he began clarinet studies at the Hochschule für Musik und Tanz Köln, where he was accepted into the master class of Ralph Manno [de].

Further education included a guest study at the Indiana University Bloomington in the US with Howard Klug,[2] as well as numerous other international master and chamber music courses, such as with Sabine Meyer, Sharon Kam, Anthony Spiri, Karl Leister, Alfred Prinz, Sir Alan Hacker, and Charles Neidich.

In the summer of 2018, he made his solo debut with Rossini's Clarinet Concerto in a specially produced Urtext edition with the La Scala Orchestra under Maestro Fabio Luisi.

[1][5] Pfeffer has notable collaborations as a soloist with the Florence Orchestra della Toscana [it] and with Markus Stenz.

Pfeffer also makes special arrangements for prominent colleagues such as Ralph Manno, Jonathan Cohler, Andrew Marriner, Gabor Varga, Pavel Vinnitsky, Sérgio Fernandes Pires, Anette Maiburg [de], Sebastian Manz, Guido Schiefen [de], Sabine Meyer, Andreas Ottensamer, and the Signum Saxophone Quartet.