In the field of contemporary music, Berger recorded works by John Cage, Toshio Hosokawa, Adriana Hölszky and Sofia Gubaidulina.[2][4] He is the artistic director of the festivals Eckelshausener Musiktage [de] and Asiago Festival in Italy.[2]
He authored Irritationskraft in the Hindemith-Jahrbuch 1992, Einheit in der Vielfalt - Vielfalt in der Einheit in the research magazine of the Mainz University in 1998, and Zeit und Ewigkeit for Cardinal Karl Lehmann in 2001, among others.
Berger has taught at the Musikhochschule Augsburg from 2000, serving as the deputy director of its Leopold Mozart Centre from 2010.[2] He plays a cello built by Andrea Amati in 1566.[5]
Inspired by MOZART (with Margarita Höhenrieder). Variations from Die Zauberflöte, Große Sonate für Violoncello und Klavier E-Dur op. 19, Sonate für Violoncello und Klavier Nr. 3 A-Dur op. 69[6]
Luigi Boccherini: Cello Sonatas, vol. 1,[7] 2[8] and 3[9]
The Unknown Beethoven: Works for Violoncello and Piano (2011)[10]
Giuseppe Tartini: Cellokonzert in A-Dur und D-Dur, Sinfonia pastorale, Sinfonie D-Dur. (with Süddeutsches Kammerorchester Pforzheim)[11]
Johann Sebastian Bach: Sechs Suiten für Violoncello Solo - Julius Berger, violoncello, 1997, WERGO – WER 4041-2, WERGO – 280 041-2