Sub Arturo plebs

Sub Arturo plebs – Fons citharizantium – In omnem terram is an isorhythmic motet of the second part of the 14th century, written by an English composer known by the name of Johannes Alanus or John Aleyn.

The middle voice or motetus, which has six six-line stanzas, first contains the praise of a succession of biblical and historical figures, each of whom is credited with a founding role for music and composition: the biblical Jubal (here misspelled as "Tubal"), the ancient philosophers Pythagoras and Boethius, Pope Gregory I, and the medieval music theorists Guido of Arezzo and Franco of Cologne.

The fifth stanza then spells out a rule for the performance of the piece itself, describing its structural plan (see below for an in-depth analysis): Huius pes triplarii bis sub emiolii normis recitatur ut hii pulsent Dominum, quorum munum nominum[4] triplo modulator The tenor ["pes", i.e. 'foot'] of this three-part piece is recited twice under the rule of the Hemiola [i.e. in a proportion of 2/3], so that those whose name roll the triplum sings may praise the Lord.

Finally, the last stanza of the motetus names the composer of the piece himself, "J. Alanus", who introduces himself as "the humblest and most insignificant" and prays for protection against envy:[2] Illis licet infimus J. Alanus minimus sese recommendat, quatenus ab invidis ipsum sonis validis laus horum defendat.

The third, upmost voice (triplum), in nine five-line stanzas, describes the flourishing of musical art at the contemporary English royal court, and contains the praise of a series of named English musicians of the composer's own time or recent past (thus contrasting with the motetus and its emphasis on ancient figures).

[5][6] The composer himself, identified as one John Aleyn, can be traced as the holder of various church offices ("King's clerk" at St. Paul's Cathedral, London, in 1361; a canon at Windsor, 1362; member of the Chapel Royal at least from 1364; died 1373).

[3] From various political allusions in the text, in connection with what is known about the named musicians, Brian Trowell and Ursula Günther have conjectured that the work was written for a specific historical event, the festivities at Windsor Castle on St. George's Day, 1358, when the knights of the Order of the Garter gathered to celebrate the English victory at the Battle of Poitiers two years earlier.

Bowers comments on the idea that an English composer might have been the first to invent this technique:[7] There is nothing inherently improbable in this suggestion: not everything new in fourteenth-century composition had to come out of France […] And of course, as far as the originator was concerned, the occasion of its invention was not the conscious inauguration of a major formal development in the history of musical design; to him it was a smart but one-off party trick (of the originality of which he was justifiably proud)The motet is known from three contemporary manuscript sources.

[6] The second source is Codex Bologna, Civico Museo Bibliografico Musicale, Ms. Q 15, a collection that otherwise represents a somewhat later repertoire with many works from the early 15th century.

A third manuscript was discovered in a private collection in the 1980s, in the form of a single sheet of music that was found bound into a 15th-century book.

In the Bologna manuscript, there is a repetition sign consisting of three vertical bars "|||", followed by the three standard mensuration signs written one over the other: a full circle with a dot in the middle, an empty circle, and an empty semicircle; in this case, the second repetition indicates tempus perfectum cum prolatione minore.

The triplum moves in tempus imperfectum cum prolatione maiore (6/8 time) throughout, no matter what the current meter of the tenor is; this results in complex patterns of overlap and syncopation.

King Edward III and Edward, the Black Prince were the two royal personalities with whom the motet is directly connected.
The Battle of Poitiers . According to one hypothesis, the motet was written for the occasion of the royal festivities in celebration of the English victory.
Structural schema of the isorhythmic tenor.
Top: Underlying Gregorian chant melody.
Second staff: Tenor as notated in Mensural notation , with the three mensuration signs defining the pattern of threefold diminution
Staff 3–5: Tenor partially transcribed in modern notation. Each of the three repetitions of the tenor ( colores ) is faster by a factor of 2/3; each color contains three taleae repeating the same rhythmic pattern. Only the beginning notes of each talea are shown here.
Polymetric structure between the three voices. This example shows the first rhythmic unit (talea) of the third, diminished, repetition of the tenor (color) . The tenor moves in 2/4 time, the triplum simultaneously in 6/8 time. The motetus shifts between 3/4, 6/8 and 2/4 time, indicated by notes written in red in the original source. The same pattern in all three voices repeats twice more in the remaining two taleae . Since the length of the tenor talea (16 x 2/4) cannot be divided into 6/8 bars, the triplum has to put in one isolated 2/4 bar at the end of each talea . [ 3 ] There is an alternative reading proposed by some editors: according to them, the note "g" in the third-but-last bar in the triplum , marked in purple here, is to be read as a simple undotted quaver (an imperfect semibreve). Then, the triplum will maintain its 6/8 movement throughout, but its second and third talea will not be perfectly aligned with those of the other voices, being shifted back by one eighth note with each repetition of the pattern. [ 2 ] [ 5 ] [ 9 ] [ 10 ]