FIG. 2-1 Notker Balbulus, a ninth-century monk from the Swiss monastery of St. Gallen, shown in an illumination from a
manuscript probably prepared there some 200 years later. He looks as though he is cudgeling his brain to recall a longissima
melodia, as he tells us he did in the preface to his Liber hymnorum (Book of hymns), which contains some early examples of
prosulated melismas known as sequences.
Also evidently exaggerated in his telling is the dependency of the sequence, as Notker and others
actually practiced it in the late ninth century, on the earlier sequentia described by Amalar. Only a handful
of surviving sequences (out of the thirty-three in Notker’s book, only eight) can be linked up with a known
sequentia melisma. By the time Notker completed his book, the sequence had already matured into a
substantial composition, fresh in both words and music and novel in style, that was sometimes (but far
from always) modeled on a liturgical Alleluia melody. It is of course possible that a lost or unrecorded
sequentia lurks behind each of Notker’s “hymns.” But to assume that this is the case would be to confuse
the origin of the genre with the origin of each individual specimen (as if every symphony were assumed to
be an operatic overture because, as historians have learned, the earliest ones were). That kind of false
assumption about origins is known as the “genetic fallacy.” To illustrate the early sequence we can
examine two specimens from Notker’s own Liber hymnorum, reminding ourselves that Notker himself
was able to notate only the texts of his sequences; the melodies come from later manuscripts that may or
may not transmit them exactly as Notker composed or adapted them in the ninth century. Angelorum ordo
(Ex. 2-4a) represents the earliest stage, a simple prosulated sequentia melisma that belongs to the
Alleluia Excita Domine (third Sunday in Advent). It conforms to Notker’s description of how the
sequence was born. The little melodic repetitions are of the kind we have already encountered in many
melismatic chants.
Altogether different is Rex regum (Ex. 2-4b), a mature sequence that happens to share its text incipit
with one of the items in Ex. 2-2. Its opening melodic phrase is artfully derived from the Alleluia Justus ut
palma (Ex. 1-6); there are other similarities between the two melodies as well. The sequence may thus
have been meant to link up with that particular Alleluia (sung at St. Gallen, Notker’s monastery, at the
Mass commemorating St. John the Baptist), but there is no reason to suppose it would have been limited
to that use. The melodic resemblance being approximate rather than exact, it has effect of an allusion: an
honorific, like those in the text, that might compliment any distinguished churchman. In any case, the
reference to Justus ut palma is not in this case the automatic result of an adaptive process but a deliberate
artistic touch, replete with a couple of neumes that in this context suggest flourishes.
Thereafter, the sequence proceeds in strictly syllabic couplets, successive pairs of lines sung to
repeated portions of the melody. (In sequences of a later date, when texts in rhymed verse replaced the
earlier “prosa” type, the couplets are often called “paired versicles.”) There is no preexisting sequentia
melisma with such a regular structure, but it would remain standard for sequences for the next three