In an interview with the music philosopher Marlies De Munck, Björn Schmelzer analyses mediaeval polyphony as ‘contre nature’ – an unnatural monstrosity that challenged the limits of earthly possibility. In his acclaimed, enthralling style, the graindelavoix frontman shows how polyphonic music evolved from crisis into controversy, with characters including the 11th century ecclesiastical scholars who were scandalised by this ‘aberration’ and 14th century composers who incorporated the criticism into their scores with a self-depreciating wink. Expect a fascinating perspective on music as a gauge of standards and a disruptor of convention, in an introduction to the concert by graindelavoix.