On 31 October 1517, Martin Luther nailed his Disputation about the power of indulgences to the door of All Saints’ Church in Wittenberg : that was the starting point of the Reformation. In response, the Catholic Church summoned, between 1545 and 1563, a council in Trent. In this political and theological debate that left its mark on all the 16th century – and brought a form of modernity – aesthetics were not absent from discussion. Quite the contrary : it triggered some major changes in this field. These are the object of our concert, along with the interactions between aesthetics, politics and theology, with the purpose to shed light on the origins and the nature of the Missa Papae Marcelli composed in 1562 by Palestrina, at the time of the Council of Trent.