Continuum in 9 (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
I. (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
II. (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
III. (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
Largo - Vivace - Largo (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
String Quartet No. 1 (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
String Quartet No. 23 (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
String Quartets (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)
Urgent Call (Stephan Thelen, Gebhard Ullmann, Udo Agnesens, Al Pari Quartet)