# A Dictionary of Music and Musicians/Recte et Retro, Per

From volume 3 of the work.
​RECTE ET RETRO, PER (Imitatio cancrizans, Imitatio per Motum retrogradum, Imitatio recurrens; Ital. Imitazione al Rovescio, o alla Riversa; Eng. Retrograde Imitation). A peculiar kind of Imitation, so constructed that the melody may be sung backwards as well as forwards; as shewn in the following Two-Part Canon, which must be sung, by the First Voice, from left to right, and by the Second, from right to left, both beginning together, but at opposite ends of the Music.
The earliest known instances of Retrograde Imitation are to be found among the works of the Flemish Composers of the 15th century, who delighted in exercising their ingenuity, not only upon the device itself, but also upon the Inscriptions prefixed to the Canons in which it was employed. The Netherlanders were not, however, the only Musicians who indulged successfully in this learned species of recreation. Probably the most astonishing example of it on record is the Motet, 'Diliges Dominum,' written by William Byrd for four voices—Treble, Alto, Tenor, and Bass—and transmuted into an 8-part composition, by adding a Second Treble, Alto, Tenor, and Bass, formed by singing the four First Parts backwards. It is scarcely possible to study this complication attentively, without feeling one's brain turn ​giddy; yet, strange to say, the effect produced is less curious than beautiful.
There is little doubt that the idea of singing music from right to left was first suggested by those strange Oracular Verses which may be read either backwards or forwards, without injury to words or metre; such as the well-known Pentameter—
Roma tibi subito motibus ibit amor.
or the cry of the Evil Spirits—
In girum imus noctu ecce ut consumimur igni.
The Canons were frequently constructed in exact accordance with the method observed in these curious lines; and innumerable quaint conceits were invented, for the purpose of giving the Singers some intimation of the manner in which they were to be read. 'Canit more Hebræorum' was a very common Motto. 'Misericordia et veritas obviaverunt sibi' indicated that the Singers were to begin at opposite ends, and meet in the middle. In the Second 'Agnus Dei' of his 'Missa Græcorum,' Hobrecht wrote, 'Aries vertatur in Pisces'—Aries being the first Sign of the Zodiac, and Pisces the last. In another part of the same Mass he has given a far more mysterious direction—
Tu tenor cancriza et per antifrasin canta, Cum furcis in capite antifrasizando repete.
This introduces us to a new complication; the secret of the Motto being, that the Tenor is not only to sing backwards, but to invert the intervals ('per antifrasin canta'), until he reaches the 'Horns'—that is to say, the two cusps of the semicircular Time-Signature after which he is to sing from left to right, though still continuing to invert the Intervals. This new Device, in which the Intervals themselves are reversed, as well as the sequence of the notes, is called 'Retrograde Inverse Imitation' (Lat. Imitatio cancrizans motu contrario; Ital. Imitazione al contrario riverso). It might have been thought that this would have contented even Flemish ingenuity. But, it did not. The Part-Books had not yet been turned upside down! In the subjoined example, we have endeavoured to show, in an humble way, the manner in which this most desirable feat may also be accomplished. The two Singers, standing face to face, hold the book between them; one looking at it from the ordinary point of view, the other, upsidedown, and both reading from left to right—that is to say, beginning at opposite ends. The result, if not strikingly beautiful, is, at least, not inconsistent with the laws of Counterpoint.
This species of Imitation was indicated by the Inscriptions, 'Respice me, ostende mihi faciem tuam,' 'Duo adversi adverse in unum,' and others equally obscure. The last-named Motto graces Morton's 'Salve Mater'—a triumph of ingenuity which, no doubt, was regarded, in its time, as an Art-Treasure of inestimable value. The style was, indeed, for a long time, exceedingly popular; and, even as late as 1690, Angiolo Berardi thought it worth while to give full directions, in his 'Arcani Musicali,' for the manufacture of Canons of this description, though the true artistic feeling—to say nothing of the plain common-sense—of the School of Palestrina had long since banished them, not only from the higher kinds of Ecclesiastical Music, but from the Polyphonic 'Chanson' also. This reform, however, was not effected without protest. There were learned Composers, even in the 'Golden Age,' who still clung to the traditions of an earlier epoch; and, among them, Francesco Suriano, the Second 'Agnus Dei' of whose Missa 'Super voces musicales' contains a Canon, with the Inscription, 'Justitia et Pax osculatæ sunt,' in which the Guida, formed on the six sounds of the Hexachordon durum, is sung, by the First Tenor, in the usual way, and in the Alto Clef, while the Cantus Secundus replies, reading from the same copy, in the Treble Clef, backwards, and upsidedown. But, in this instance, the simple notes of the Guida are accompanied by six 'Free Parts,' by the skilful management of which the Composer has produced an effect well worthy of his reputation.
Retrograde Imitation has survived, even to our own day; and, in more than one very popular form. In the year 1791, Haydn wrote, for his Doctor's Degree, at the University of Oxford, a 'Canon cancrizans, a tre' ('Thy Voice, O Harmony') which will be found in vol. i. p. 710b; and he has also used the same Device, in the Minuet of one of his Symphonies. Some other modern Composers have tried it, with less happy effect. But, perhaps it has never yet appeared in a more popular form than that of the well-known Double Chaunt by Dr. Crotch.
[ W. S. R. ]
* ↑ Reprinted by Hawkins, 'History,' ch. 96.
* ↑ Versus recurrentes, said to have been first invented by the Greek Poet, Sotades, during the reign of Ptolemy Philadelphus. The examples we have quoted are, however, of much later date; the oldest of them being certainly not earlier than the 7th century.
* ↑ The entire Mass is reprinted, from the original edition of 1609. in vol. i. of Proske's 'Selectus novus Missarum'; and the Canon is there shewn, both in its ænigmatical form, and in its complete resolution.