He has lived and worked in Bern, and contributed significantly to making the city important for the contemporary performance art scene.
[2] Klassen's work had been influenced by a multitude of co-operations with international artists from the backgrounds of acting, music, visual art and intermedia.
Between 1980 and 1997, Klassen held a teaching position at the Schauspielschule am Konservatorium für Musik und Theater Bern, and from 1987 to 1995 he taught at the F+F School for Art and Media Design Zurich.
On this occasion, Klassen announced the „death of theatre“, and postulated performance art as the only adequate artistic succession.
The collective bases its work among others on the principle that “all is possible”, and continues participating in numerous performance art festivals worldwide.