Annotations to James Joyce's Ulysses/Ithaca/651

Annotations
secreto   (Latin) privately; quietly. In the Latin Tridentine Mass, some prayers and texts are to be chanted or spoken by the celebrant in a low voice so that the congregation cannot hear.

The 113 th   Psalms 113 in the Latin Vulgate translation of the Bible (Psalms 114 in the King James Bible).

modus peregrinus   (Latin) wandering mode. When passages of the Latin Tridentine Mass are to be intoned rather than sung, the celebrant improvises a chant based on one of several traditional reciting tones. These include eight psalm tones and the tonus peregrinus or wandering tone. The eight psalm tones were associated with the eight church modes; in the Middle Ages the tonus peregrinus came to be associated with the ninth mode, the Aeolian.

In exitu Israël de Egypto : domus Jacob de populo barbaro   (Latin) When Israel went out of Egypt : the house of Jacob from a people of strange language. According to the Missale Romanum of the Latin Tridentine Mass, Psalms 113:1 (Psalms 114:1 in the King James Bible) is to be sung as part of the Alleluia, which follows the Graduale, on the 21st Sunday after Pentecost. The Gradual is sung after the Epistle; it is followed by the Alleluia and the Gospel. In Eastertide, the Gradual is usually omitted and an Alleluia is sung in its place; in the Missa ad Postulandum Gratiam bene Moriendi (Mass to ask for a Good Death), this Alleluia is based on In exitu. Nowhere in the Missal is the celebrant directed to sing the Psalm verses of the Alleluia secreto.

In Dante's Purgatorio 2:46 ff. this Psalm is sung by the souls of the dead as they are being ferried to the foot of Mount Purgatory. In his Letter to Can Grande della Scala, Dante quotes this verse and uses it to illustrate his method of interpreting sacred scripture's four levels of meaning (literal, allegorical, moral and anagogical).