[very] -- Lauda Sion
Thomas Aquinas’s chant sequence Lauda Sion has a very intricate structure. It starts out with 18 tercets. The rhyme scheme AAB CCB groups them into pairs.
Lauda Sion Salvatorem
Lauda ducem et pastorem
In hymnis et canticis.
Quantum potes, tantum aude:
Quia major omni laude,
Nec laudare sufficis.
Laudis thema specialis,
Panis vivus et vitalis,
Hodie proponitur.
Quem in sacrae mensa coenae,
Turbae fratrum duodenae
Datum non ambigitur.
Sit laus plena, sit sonora,
Sit jucunda, sit decora
Mentis jubilatio.
Dies enim solemnis agitur,
In qua mensae prima recolitur
Hujus institutio.
In hac mensa novi Regis,
Novum Pascha novae legis,
Phase vetus terminat.
Vetustatem novitas,
Umbram fugat veritas,
Noctem lux eliminat.
Quod in coena Christus gessit,
Faciendum hoc expressit
In sui memoriam.
Docti sacris institutis,
Panem, vinum, in salutis
Consecramus hostiam.
Dogma datur Christianis,
Quod in carnem transit panis,
Et vinum in sanguinem.
Quod non capis, quod non vides,
Animosa firmat fides,
Praeter rerum ordinem.
Sub diversis speciebus,
Signis tantum, et non rebus,
Latent res eximiae.
Caro cibus, sanguis potus:
Manet tamen Christus totus,
Sub utraque specie.
A sumente non concisus,
Non confractus, non divisus:
Integer accipitur.
Sumit unus, sumunt mille:
Quantum isti, tantum ille:
Nec sumptus consumitur.
Sumunt boni, sumunt mali:
Sorte tamen inaequali,
Vitae vel interitus.
Mors est malis, vita bonis:
Vide paris sumptionis
Quam sit dispar exitus.
Then he adds a line. Four paired quatrains in a similar AAAB CCCB pattern follow.
Fracto demum Sacramento,
Ne vacilles, sed memento,
Tantum esse sub fragmento,
Quantum toto tegitur.
Nulla rei fit scissura:
Signi tantum fit fractura:
Qua nec status nec statura
Signati minuitur.
Ecce panis Angelorum,
Factus cibus viatorum:
Vere panis filiorum,
Non mittendus canibus.
In figuris praesignatur,
Cum Isaac immolatur:
Agnus paschae deputatur
Datur manna patribus.
To climax, he appends yet another line.
Bone pastor, panis vere,
Jesu, nostri miserere:
Tu nos pasce, nos tuere:
Tu nos bona fac videre
In terra viventium.
Tu, qui cuncta scis et vales:
Qui nos pascis hic mortales:
Tuos ibi commensales,
Cohaeredes et sodales,
Fac sanctorum civium.
Amen. Alleluja.
Aquinas did not invent the technique of expanding stanzas by reduplicating rhymes, but Lauda Sion is surely one of its finest expressions. Although the principle of generation is basic, the results are anything but. At first glance, the 18 tercets awkwardly dominate the 4 quatrains and 2 quintains. However, 18 / (18 + 4 + 2) = 3/4, a beautifully simple fraction. Similarly, 4 / (4 + 2) = 2/3. Multiplying these two ratios gives (3/4)(2/3) = 1/2, an expression of perfect symmetry. To conclude, Aquinas breaks all constraints with the doxology “Amen. Alelluja.”, a satisfying rest from all the complexity that precedes it.