In the fifteenth century, the number of sibyls was stabilized at twelve, a number full of Christian
resonances (the minor prophets, the apostles). The twelve sibyls are best known today from
Michelangelo’s renderings on the ceiling of the Sistine Chapel. The twelve anonymous prophetic poems
Lasso set to music appeared for the first time as a supplement to a 1481 Venetian edition of a treatise on
the sibyls as prophets of Christ by Filippo Barbieri, the Inquisitor of Sicily. They were reprinted in Basel,
Switzerland, in 1545, and that, presumably, is how they found their way to the composer.
FIG. 17-5 The Cumean sibyl, as rendered by Michelangelo on the ceiling of the Sistine Chapel in Rome.
These venerable quasi-pagan mystical texts as summarized by a Christian classicistic poet obviously
demanded some form of unusual musical treatment to render their uncanny enigmatic contents. Drawing on
a kind of humanistic musical speculation that was just then rife in Italy (and to which we will return in a
couple of chapters), Lasso adopted a style of extreme, tonally disorienting chromaticism (as he proudly
proclaims in a three-line poetic prologue of his own contriving), coupled with a starkly homorhythmic,
vehemently declamatory manner that brought the weird words and the weirder harmonies very much to the
fore. The result is hair-raising, not only as an expression of religious mysticism, but as the revelation (so
to speak) of an alternative path for music that challenged the absolute validity of the ars perfecta. The
two extracts included in Ex. 17-13 are the prologue, with its brash expository sweep by fifth- and third-
relations from triadic harmonies on the extreme sharp side (as far as B major) as far flatward as E-flat
major; and the end of the Cymmerian sibyl’s prophecy, which contains the most radical single progression
in the cycle, entailing the direct motion in the altus, on the last line of text, through a diminished third
(now how are you supposed to solmize that?).
EX. 17-13A Orlando di Lasso, Prophetiae Sibyllarum, Prologue