Vier Türme [Four towers] is a visual music project by Felix Herzog. Based on a watercolour by Paul Klee, it investigates the interaction of overlaying, transparent colour fields. The project is loop-based and intended for non-linear improvisation, the present clip should therefore be regarded as a snapshot. On a musical level, similarly to the colour fields, audio loops of different time bases are layered which allow diverse patterns to be produced depending on the combination. In the production of this project both video and audio were transposed several times between the digital and analogue mechanical world. Vier Türme was produced as a Video 1 exam for Prof. Dr. Heike Sperling and Andreas Kolinski.