What is perceived as “natural” and “unnatural” in music is by no means clear-cut. In the 13th and 14th centuries there were heated discussions about this among music theorists. In particular, “metric” and “rhythm” led to many distortions. There was for instance a “long” and a “short” note, which together formed a trinity that was called “perfectio” in reference to the divine number 3. “imperfectio”, on the other hand, was associated with conditions of the human body: the symmetrical arrangement of the limbs, the heartbeat, breathing in and out. Attempts to blend these two levels resulted in music so rhythmically complicated that it was considered almost unplayable when it was rediscovered in the 20th century. In medieval times, many felt it was “against nature.” After its thorough research, however, it is now part of the fixed repertoire of early music. Whether you perceive it as “artificial” or “natural”, you can decide for yourself at this lecture. After a feigned debate between theoretica and practica, Angelika Moths, Corina Marti and students of the Musicology Institute will perform compositions from the period.