Toward the end of the Middle Ages, preachers warned of demons assigned to keep track of very specific sins. One of them was Tityvillus, an imp who specialized in collecting evidence for the negligence of the clergy and laypeople during church services. Identified by his sack, which brimmed with syllables dropped by lazy choir singers, or his sheet of parchment, on which he wrote the names of daydreamers and gossips during sermons, Tityvillus carried the proof of these transgressions back to Hell, where the Devil used them as evidence against sinners, who would suffer under the weight of enormous sacks in the afterlife as punishment for their negligence.
I heard that a certain holy man, while he was in the choir, saw a demon burdened as though with a very full sack. When he commanded the demon to tell him what he was carrying, the demon answered: “These are the misplaced syllables and words and psalm verses, which those clergy in their morning prayers have stolen from God; I keep these diligently for their accusation.” Therefore, keep watch carefully at the mystery of the altar, so that indignation does not arise over the people.
However, certain people think empty thoughts and speak idle words during sermons and in church, when they should be paying attention to what is being said. When a certain holy priest saw a demon stretching parchment with his teeth during a time of great solemnity, he commanded the demon to tell him why he was doing so. The demon responded: “I am writing down the idle words which are spoken in this church and because such words have multiplied today much more than usual because of the solemnity of the feast day, seeing that the sheet I brought with me will not suffice, I am trying to stretch the parchment with my teeth.” Hearing this, the priest began to tell this story to the people and everyone who heard it began to feel sad and contrite. While they were feeling sad and penitent, the demon who had written down the words began to erase them until the sheet was blank. Therefore, you should with all diligence and devotion give your attention to the divine office and sound teaching and eat not the bitter morsel but rather the spiritual feast.
A certain holy man saw a demon burdened as though with a full sack. When he commanded the demon to tell him what it was carrying, the demon answered, “I carry the syllables cut off from the readings and the verses of psalms which these clergy stole last night.” And the holy man asked, “What is your name?” The demon responded: “I am called Tityvillus.” This man composed a verse inspired by this answer: Fragmina Psalmorum Tytyvillus colligit horum (“Tityvillus gathers the fragments of those psalms…”).
At one time, when certain clerks in a certain secular church were singing with vigor, that is, noisily and without devotion, and raising their turbulent voices on high, a certain religious man who then happened to be present saw a certain demon standing higher up in the church and holding a long, voluminous sack in his left hand. With his right hand held out, he caught the voices of those singing and put them in his sack. When the service was over and these clerks congratulated each other, as though they had praised God vigorously and well, the man who had seen the vision said to them, “You have indeed sung well, but you have sung a sack full.” They were confused and asked him why he had said this, so he explained his vision to them. An abbot of the Cistercian order, a man of the utmost authority, told this story to me.
Vocal prayer can be divided into many parts…The ninth kind is psalmody, with the singing of the psalms. This should be done attentively, distinctly, devoutly, correctly, and succinctly…Against those who sing the psalms inattentively and without devotion and indistinctly, or those who shorten the verses of psalms, gut them of their sense, omit words, forget or leave out letters, who do not sing intelligibly, but shout at one another like birds gathered in a flock, an exemplum of Master Jacob speaks to this, when he says that a devil carrying a full sack appeared to a certain holy man. Commanded to reveal what he carried, the demon said that he was coming from a certain church of secular canons, where he had gathered this sack filled with syllables and words cut out of the psalms, from which he would accuse them in judgment.
The same master said this about the same topic: I heard Brother Gaufridus de Blevez relating that in the diocese of Sens, when a certain priest had died and should have been buried, he was summoned back from death and rose up. Among other terrible things he was saying, he reported that he had met an innumerable multitude of priests and clerics suffering terribly and oppressed under the giant sacks they were carrying. And it was said to the one asking that they were carrying syllables and words and other parts of the psalms that they had failed to utter clearly, for which they suffered the most serious punishments.