Let me introduce you to another Graeco-Latin metre: the trochaic tetrameter catalectic. Actually, you know it already - it is the metre of the two great Pange lingua hymns: the one about the Cross, written by Venantius Fortunatus for a royal Mother Superior who had succeeded in begging a Relic of the True Cross from the Emperor in Constantinople; and the one written by S Thomas for Corpus Christi. But this metre gets its first airing in the liturgical year at the OF First Evensong of Mary, Mother of God, this evening: Corde natus ex Parentis.
Tumpty is a trochee; two of them, tumpty tumpty, make up a 'trochaic metron'; four of these are described as a trochaic tetrameter; and if you chop off the very last syllable of the sixteen, what's left is a trochaic tetrameter catalectic. (Some people call it a trochaic septenarius, but then, they would, wouldn't they.) The line is very long, and, since there is a regular word-break after the eighth syllable, printers commonly split it up into two lines respectively of eight and of seven syllables.
What is surprising about this metre is that it was seen and used by the ancients as comic and vulgar (and so described by Aristotle). It is used by the great writer of New Comedy, Menander (you could go and see a nice bust of him in the Ashmolean; he more or less invented the 'situation comedy' and perfected the eternally fertile formula 'Boy loves Girl: there is an Obstacle: the help of a Clever Slave solves it so that all live happily'). In one of his 'latest' plays ('latest' in the sense that lost plays keep turning up on papyri preserved in the dry sand of the Egyptian desert), the Girl from Samos, it is used in a hilarious slapstick scene featuring Girl's comically nasty Father, Niceratus. Menander's Roman imitators adapted it into Latin, and so Plautus uses this metre in his Mostellaria for the scene where Boy, drunk, comes across Girl while she is putting her make-up on and goes for an inopportune grope.
So how did this frivolous metre come to be used for what we might think of as the stateliest and most dogma-laden hymns of our Latin tradition? I'm not sure, but I suspect that earlier Christian generations might just possibly not have seen things in exactly our way. Remember S Ambrose's phrase sobria ebrietas Spiritus: the sober inebriation of the Spirit. Perhaps the wonder of the Incarnation; or the exuberant joy of processing into Poitiers with a Relic of the Redeeming Tree; or the stunning wonder of the Eucharistic presence; might have aroused a response of exstatic exultation in Prudentius, Venantius, and Aquinas, rather than of dispassionate reflection. Perhaps such mysteries should get our hearts dancing, too.
Unfortunately, the post-Conciliar Revisers only gave us four stanzas of Prudentius' hymn Corde natus. Anglicans can find nine stanzas in the good old English Hymnal. R F Davis' superb translation used the last line in Prudentius' poem saeculorum saeculis as a refrain after each stanza (Lentini's Commission first tried to make it the last line of a doxology they were cobbling together but then realised they had made a metrical error and abandoned it). But Davis does miss one or two bits of Prudentius' vividness; Puerpera edidit portrays our Lady giving one last push in her womb, (not, as Davis' translation coyly suggests, receiving the babe in loving arms), and puer ... os sacratum protulit drills into, as Fr Zed likes to put it, the reality of physical childbirth - many fathers will remember the sense of wonder mingled with apprehension as they watched their own child proferentem its os.