The four accounts of the suffering and death of Christ, as given in the first four books of the New Testament, were customarily sung during the Catholic rites of Holy Week to plainchant, with a division of parts where direct speech is involved. It became customary in the 15th century to allow the singing of the parts of the crowd (= Latin: turba) in the biblical narrative in polyphonic settings, with a gradual extension of the polyphonic element in the next century. The best known settings of the Passion are the surviving Lutheran settings by Johann Sebastian Bach of the accounts of the Passion in the Gospels of St. Matthew and of St. John.