Another of those discussions one has after Mass ... stimulated, on this occasion, by the Corpus Christi sequence. In our vernacular Mass, it was a Cento: a Latin word, not much found in classical authors, meaning a patchwork. It is commonly used to refer to a translation which has been stitched together from different translators, taking (hoffentlich) the neatest renderings from each. In Lauda Sion the Anglican translation is a Cento; I haven't checked ... I expect some reader will know ... but I imagine Dr Neale and Fr Caswall may be substantial contributors.
The metrical and rhyming scheme in Lauda Sion is the same as in Stabat Mater. Who originated it? The 12th century poet Adam of S Victor is usually credited with it (earlier sequences not having anything like the same tight structure). Extracts from one of his sequences in this metre were used at the Office of Readings on Pentecost by those of us who use the Latin Liturgia Horarum: "Lux iucunda, lux insignis". You could call the basic line a trochaic dimeter: tumty is a trochee; a metron is two of them; here we have two metra. The last line of each stanza is the same but catalectic: i.e. the last syllable of the dimeter is missed out. The structure is deliciously emphasised by the (unclassical) heavy rhyming scheme. And I just love the way the stanzas get longer as we reach the end of the poem: there seems a pathos, a plangency, in the increasing delay before one is granred the release of the catalectic line. Look again at the last two stanzas of Lauda Sion; either in the Latin or in the English Hymnal Cento.