This complexity of opera merits being perceived, being seen, being experienced; thus all works that end up performed on stage, are rigorously analyzed beforehand.

Here he met composers Luigi Nono[2] and Karlheinz Stockhausen, which would influence Zehelein's future artistic development.

Zehelein worked with stage directors Ruth Berghaus,[15] Martin Kušej, Nicolas Brieger, Christof Nel, Neuenfels,[16] Peter Konwitchny, Joachim Schlömer, Jossi Wieler and Sergio Morabito.

The sopranos Catherine Naglestad and Eva-Maria Westbroek were members of his permanent ensemble, tenor Jonas Kaufmann a frequent guest artist.

[10][17][18] In his fifteen years Zehelein explored most of the 20th century's opera standard repertoire, such as Berg's Wozzeck and Lulu, Shostakovich's Lady Macbeth of Mtsensk, Schreker's Die Gezeichneten, Busoni's Doktor Faust, and Nono's Al gran sole carico d'amore and Intolleranza 1960.

[19] Zehelein performed works of the composers Lachenmann, Jungy Pagh Pan, Hans Zender and Rolf Riehm.

[20] Zehelein argued that as Richard Wagner wrote the four music-dramas of the Ring over many years, changing dramaturgical ideas in the process, each opera could be treated as a stand-alone work.

[23][24] Numerous CD and DVD productions document Zehelein's interest in modern works and new staging concepts.

Stuttgart CD productions include Nono's Intolleranza 1960(1995) and Al Gran Sole Carico D'Amore (2001), as well as Lachenmann's Das Mädchen mit den Schwefelhölzern (2003); Zehelein's productions on DVD: Handel's Alcina (1999), Hartmann's Simplicius Simplicissimus (2005), Mozart's La finta giardiniera [2006) and Wagner's Der Ring des Nibelungen,(2003).

The Theaterakademie is a university level academy offering BA and MA courses in directing, acting, musical theatre, singing, opera, make up, dramaturgy, theatre- film- and television criticism, set and costume design.