Engagements with top international orchestras such as the Berlin Philharmonic, the Chicago Symphony Orchestra, the Concertgebouw Orchestra Amsterdam, the Staatskapelle Dresden, the London Symphony Orchestra, the New York Philharmonic Orchestra, the NHK Orchestra Tokyo, the Vienna Philharmonic and the Vienna Symphony Orchestra quickly followed under conductors such as Claudio Abbado, Christoph von Dohnányi, Bernard Haitink, James Levine, Lorin Maazel, Zubin Mehta, Václáv Neumann, Dennis Russell Davies, Wolfgang Sawallisch, and Franz Welser-Möst.

In addition to his solo work, chamber music has become a special focus of Christian Altenburger's artistic work. He is a welcome guest at international chamber music festivals such as the Meiringen Music Week, the Casals Festival in Prades, the Naantali Music Festival, and the Allegro Vivo Festival, and enjoys performing with colleagues and friends such as Silke Avenhaus, Patrick Demenga, Ralf Gothoni, Heinz Holliger, Reinhard Latzko, Michel Lethiec, Andrea Linsbauer, Arto Noras, Jasminca Stancul, and Melvyn Tan.

From 1999 to 2005 he served as artistic director of the Mondseetage festival together with actress Julia Stemberger, from 2003 to 2019 he was responsible for the artistic direction of the Schwäbischer Frühling chamber music festival, and since 2006 he has been artistic director of the Loisiarte festival, where he also defined the program concept.

Recordings for the labels Classic Amadeo, CPO, Guild, Japan Victor, Oehms Classics, ORF, Pro Arte and Sony document the artist’s broad repertoire.

After many years as a professor at the Hanover University of Music, Christian Altenburger was appointed professor at the University of Music and Performing Arts Vienna in 2001. He also regularly gives master classes at the Mozarteum International Summer Academy, the Allegro Vivo Festival, the Mendelssohn Festival in Hamburg, and at Haus Marteau.

Jury work at international competitions such as the Isang Yun Competition in Korea, the International Classic Violin Olympus Competition, the Spohr Competition in Weimar, the Michael Hill Competition in New Zealand and the Lipizer Competition complements Christian Altenburger's diverse activities.