A model for the Roman liturgical order for processions on Sundays was Easter, the festal day described in Ordo Romanus I, rather than the preceding Sunday, perhaps a more obvious pattern for a procession within the Proprium de tempore.Michel Andrieu, ed., Les Ordines Romani du haut Moyen Age, 5 vols. (Louvain, 1931, 1948–61) II, 68–9, Ordo I, 5: ‘nam prima feria regio tertia, id est paschae, secunda feria’, etc. ; I, 7: ‘Diebus itaque sollemnibus, id est Pascha’. ‘Id est’ might be interpreted ‘for example’. Note that Easter is only one example of the papal processional procedures found only in this ordo. See John F. Baldovin, The Urban Character of Christian Worship, Orientalia Christiana Analecta 228 (Rome, 1987), 131–2. The present study originated as a paper for the session ‘Music for Festal Days’ at the 34th International Congress on Medieval Studies, Kalamazoo, Michigan, May, 1999. The singing by the Hebrew people of Hosanna and Benedictus qui venit to acclaim the one progressing into Jerusalem on Palm Sunday would seem to be the ideal archetype for a procession with song to replicate a biblical event, reported uniformly in all four Gospels.Matt. 21:8–9; Mark 11:8–10, Luke 19:36–8 (with different wording); John 12:12–13. The Old Testament presaging of Benedictus is Psalm 117:26. The visual replay with the symbols of olive branches and palm fronds and the commemorative Palmesel, integral to the procession, have been studied in critical detail by Karl Young and many who have followed in the wake of his pathbreaking The Drama of the Medieval Church. Much of the music has been expertly studied by Terence Bailey. On musical and prayer formularies from the typikon and early Western patristic citations (i.e. Bede, Aldhelm, Amalarius and Drogo of Metz), see Hermann J. Gräf, Palmenweihe und Palmprozession in der lateinischen Liturgie (Kaldenkirchen, 1950), 10–15, 30–2. See also Karl Young, The Drama of the Medieval Church, 2 vols. (Oxford, 1962), I: 90–8, 519, 527, 533, 549; Terence Bailey, The Processions of Sarum and the Western Church (Toronto, 1971), 33–40 (Examples 6–14); 166–7 (Table 2). (The acclamation Benedictus qui venit–Hosanna in excelsis that follows the Sanctus of the Mass precluded movement by its position within the liturgy.) By the time of the pilgrim Egeria, who visited Jerusalem in the early 380s, the commemoration of the Evangelists' historiae had engendered a meeting at the very spot where in biblical times infants, strewing palms sang the celebrated Benedictus verse, now converted into a refrain.‘Et jam cum coeperit esse hora undecima [die dominica] legitur ille locus de evangelio, ubi infantes cum ramis vel palmis occurrerunt Domino, dicentes: Benedictus qui venit in nomine Domini. Et statim levat se episcopus et omnis populus; porro inde de summo monte Oliveti totum pedibus itur. Nam totus populus ante ipsum cum hymnis vel antiphonis, respondentes semper; Benedictus qui venit in nomine Domini’. [Peregrinatio ad loca sancta] Itinerarium 31, 1, ed. Pierre Maraval, Egérie: Journal de Voyage, Sources Chrétiennes 296 (Paris, 1982), 274; trans. John Wilkinson, Egeria's Travels to the Holy Land (Jerusalem, 1981), 133. Other translations and descriptive material are found in Cyrille Vogel, Medieval Liturgy: An Introduction to the Sources, rev. and trans. William G. Storey and Niels Krogh Rasmussen (Washington, DC, 1986), 11. On the date of Egeria's report, see Peter Jeffery, ‘The Earliest Christian Chant Repertory Recovered: The Georgian Witnesses to Jerusalem Chant’, Journal of the American Musicological Society, 47/1 (1994), 2–3. Perhaps a half-century before, Chrysostom (Homilia habita in magnum hebdomadam 2) had allied the Hosanna exclamation with the exhortation ‘Praise the Lord, O my soul!’ of Psalm 145. See James McKinnon, ed., Music in Early Christian Literature (Cambridge, 1987), 83 (no. 175); cf. Thomas J. Talley, The Origins of the Liturgical Year (Collegeville, MN, 1991), 186. For the Palm Sunday agendas according to other Eastern practices (e.g., Armenian, Georgian and the Anastasis Typikon) see Baldovin, The Urban Character, 77, 80–1, 98.