Celebrated today as the father of modern emotional music and the pioneer of opera, Claudio Monteverdi was attacked in his own time for destroying the sacred rules of art, mistreated and fired by his ducal employer, robbed by highwaymen, and driven to alchemy and the priesthood before writing commercial hits in his seventies. This episode begins in Cremona in 1567, where an apothecary’s son published sacred music at fifteen and mastered Renaissance polyphony, a system treated as applied mathematics reflecting the divine ratios of the music of the spheres, in which dissonance was not a creative choice but a moral failing.

The conversation follows his hiring at the Gonzaga court in Mantua as a mere string player, the public attack by theorist Giovanni Maria Artusi on music that had not even been published, and Monteverdi’s defense of a seconda pratica in which the text is master and the music its servant. It covers L’Orfeo in 1607 with its nearly forty instruments assigned to characters and moods, the surviving Lament from L’Arianna, the deaths of his wife Claudia and a teenage student singer, his dismissal in 1612, and his 1613 appointment to St Mark’s in Venice. It closes with a son arrested by the Inquisition, a pearl necklace sold for his defense, alchemy experiments with Murano glass, the plague that killed 45,000 Venetians, ordination in 1632, the opening of the first public opera house in 1637, The Coronation of Poppea, his death in 1643 and the three centuries of obscurity that followed.

• Why Renaissance polyphony treated a clashing note like claiming two plus two equals five
• The prima pratica versus seconda pratica explained as autocorrect versus messy all-caps emotion
• How L’Orfeo decoupled instruments from the choir and used brass to paint the underworld
• How the San Cassiano ticket model shifted opera from royal parties to a commercial industry
• Why sparse notation left the architect of opera forgotten until the twentieth century