We’re familiar with sensory illusions – the Doppler effect, M. C. Escher’s staircases, or the endlessly ascending tone (Shepard tone / scale), used by György Ligeti, among others. In the late 1960s, the French composer and sound researcher Jean-Claude Risset discovered an auditory illusion: the Risset rhythm. Risset experimented with a rhythmic structure that becomes slower or faster – seemingly without end. (Of course, that’s not actually the case, but that’s how we perceive it.) Risset himself did practically nothing with this discovery, and the phenomenon remained an obscure, unexplored topic. There were no realizations for acoustic instruments or live performers – until now. It was Sebastian Gramss – presumably the first worldwide – who developed the “Risset rhythm” under the name Helix into an extremely versatile approach, applying it systematically with a wide variety of ensembles and musicians. In our interview, Gramss grins mischievously: “Got a little time on your hands?” Then...