Ensemble Sortisatio is a quartet (viola, oboe/cor anglais, bassoon and guitar) founded by violist Matthias Sannemüller in 1992 in Leipzig, Germany.

Members of the quartet are Walter Klingner (oboe and cor anglais), Axel Andrae (bassoon), Matthias Sannemüller (viola) and Thomas Blumenthal (guitar).

The Swiss/Austrian Groupe Lacroix (Marianne Schroeder, John Wolf Brennan, Jean-Luc Darbellay, Christian Henking, Michael Schneider, Michael Radanovics and Alfons Karl Zwicker) and Thüring Bräm dedicated 8 Pieces on Paul Klee to the Anniversary of the Central German Broadcasting.

Hong Kong composer Chan Wing-wah dedicated a trio Oriental Garden on Paul Klee in Bern & Winterthur to the Ensemble Sortisatio.

Sortisatios second record consists of compositions written by Michael Stöckigt, Reiner Bredemeyer, Gerd Sannemüller, Pēteris Vasks from Latvia, Thomas Böttger, Jean-Luc Darbellay from Switzerland, Helmut Bieler and Jean-Louis Petit from France.