YEARBOOK OF THE ALAMIRE FOUNDATION

VIRTUS SCRIPTORIS: STEPS TOWARDS A TYPOLOGY OF ILLUSTRATION BORROWING IN MUSIC THEORY TREATISES
books and church decoration; while sleeping, Jacob dreamed of a ladder reaching
from earth to heaven, and of angels walking up and down the ladder to provide uninterrupted
contact between the two realms. 34
Beyond the realm of Biblical connections, the illuminator of Oxford, Bodleian
Library, MS Digby 83 – an anonymous compilation of astronomy, botany, zoology,
geography, and other natural and occult sciences entitled Opusculum de ratione spere,
with complex illustrations appearing on nearly every page – used the ladder on folio
3v to show, in the context of a philosophical tract, dualities such as matter and spirit,
generatio and corruptio, incrementum and diminutio, concretio and discretio, and so
on. 35 In other disciplines, such as Roman and canon law, the ladder was chronologically
the first visual aid developed to illustrate the concept of consanguinity, as each
of the steps, called gradus in Roman jurisprudence, was allotted to one generation.
While reading the legal precepts illustrated by such a diagram, one would perform a
visual excursion up and down the ladder, ascending to the common ancestor or
descending to the members of the newer generations. 36
Whether as an icon such as the ones found in the innumerable copies of Boethius’s
De musica, 37 or as an extension or reinterpretation of the ladder icon, the monochord
is often drawn as a straight line partitioned into several segments to show intervals
and proportions. More ambitious renditions of it, however, resemble a real-life measuring
tool, or a more ‘playable’ string instrument such as the monachordum diatonicum
found on folio 47r of Oxford, Bodleian Library, MS Bodley 842. 38 Sometimes
the image of the monochord recalls parts of diagrams of lunar and solar eclipses or
some other representation of a cosmic scheme found in tracts such as Giovanni de
Sacrobosco’s De sphera. In the same vein, the assiduously copied manuscripts of
Plato’s Timaeus in the translation of Calcidius (known to the West in the twelfth century)
include an abundance of illustrations for astronomic phenomena; 39 these in turn
could have provided models for the drawing of the type of monochord appearing, for
34 For example, the visual couterpart for this portion of the legend is pictured as scala iacobi per quam
descendunt angeli in The Hague, National Library of the Netherlands, MS MMW 10B34, a manuscript
of the fourteenth-century Speculum humane salvationis copied in Cologne around 1450. The image
can be seen at The Hague, Handschriften, by selecting the Expert Search link and using the word ladder
to perform a Words from descriptions search under Images (see footnote 6).
35 The manuscript can be seen by following the Bodleian Library link at Early Manuscripts at Oxford.
36 Arbre généalogique, in R. NAZ, Dictionnaire de droit canonique contenant tous les termes du droit
canonique avec un Sommaire de l’Histoire et des Institutions et de l’état actuel de la discipline, 7 vols.,
Paris, 1935–1965, 1, col. 901.
37 For a list of extant codices, see C.M. BOWER, Boethius’s De Institutione musica: A Handlist of Manuscripts,
in Scriptorium, 42 (1988), pp. 205–251.
38 The diagram is independent of the music theory treatises included in the manuscript; see RISM B/3/4,
p. 113: Mesure de monochorde. The image can be seen by following the Bodleian Library link at Early
Manuscripts at Oxford.
39 See, for instance, Oxford, Bodleian Library, MS Digby 23, fol. 52r; the image can be seen by following
the Bodleian Library link at Early Manuscripts at Oxford. The manuscript was bequeathed to Osney
Abbey by Master Henry of Langley (d. 1263?).
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