This is a Christopher Willcock extravaganza for processing on Palm Sunday. I can only see this used for processing around a church as the cantor or choir will need to be near the assembly, so this is perhaps not for processing a long way to the church.
The Ostinato refrain for the assembly anchors the cantor with the sequence:
v.1/refrain/v.2/refrain/v.1/refrain/v.3/refrain/v.1/coda.
OCP have the sheet music for you to buy and also they give you the text in their preview.