The piece "Woher diese Zärtlichkeit" is a theatre play and concert that combines poems by Marina Zwetajewa with chamber music and songs by Dmitri Schostakowitsch. The visualizations of swarm simulations are projected on the stage setting in form of a large and reactangular metallic sculpture. The swarm simulation is played live as a visual instrument that complements the musical performance. Throughout the dramatic development of the piece, the swarm simulation coalesces into and dissolves from sentences and words in Marina Zwetajewa's poems.

This project has been realized as a collaboration:

Rachel Eisenhut: Dramaturgy
Eugen Eisenhut: Stage Design
Daniel Bisig: Simulation and Vide
Ueli Riegg: Stage Light
Walter Prossnitz: Piano
Christina Daletska: Mezzo-soprano
Krešimir Stražanac: Bass-baritone
Yuka Tsuboi, Sarah Kilchenmann, David Schneebeli and Julien Kilchenmann: Galatea Quartett