“Panta Rhei” – everything flows. Also a flood of visitors – 40,000 guests – on Saturday in the Linz Donaupark to the sound cloud of the same name. “We step into the same river and yet not into the same. We are and we are not.” Robert Dornhelm and co-director Christoph Engel stage Heraclitus parable for the eternal change of life on the Danube in a powerful visual manner. A gigantic harp, actually played by Joel von Lerber on a pedestal, glides by.