After graduating, he began studying at the Juilliard School in New York in Dorothy DeLay's class, on the recommendation of Zubin Mehta.
Further engagements as a soloist followed in concerts with orchestras such as the Vienna Philharmonic, the Berlin Philharmonic, the London Symphony Orchestra, the New York Philharmonic, and the Chicago Symphony Orchestra under conductors such as Claudio Abbado, Bernard Haitink, James Levine, Zubin Mehta and Wolfgang Sawallisch.
[1] From 1990 to 2001 he taught as professor of violin at the Hochschule für Musik, Theater und Medien Hannover.
Since 2003 he has been artistic director of the chamber music festival Schwäbischer Frühling, and since 2006 of the Loisiarte in Langenlois.
During a burglary in Altenburger's apartment on 29 May 2007, thieves stole a supposed Stradivari violin from the year 1680 worth around 2.5 million euros and a Vuillaume violin worth around 120,000 euros, which were found undamaged by the police on 5 June 2007.