This gesture (reconstructed by me) corresponds to mehuppakh ("returned, turned around") -- a name befitting the degree which completes the octave in prosody. This sign is called yetiv by the Masorah and the early treatises when it is found in certain grammatical contexts; in such cases, it is put at the beginning of the word. (Allegedly, it is simply a graphically and melodically transformed version of the superlinear sign pashta!) Yet even so, the Masorah lists eleven exceptional cases where "yetiv" is placed where mehuppakh is normally placed, and which therefore may "cause confusion to the reader". A much simpler explanation is that one musical sign is being used to give different kinds of emphasis to the verbal text. "Yetiv" would thus be a name added after the creation of the accent system, designed to give a special domain to a grapheme which originally meant one and the same thing as mehuppakh.

Haïk-Vantoura never specifically addressed the significance of the positioning of
mehuppakh (on some words) before the vowel-point, and usually slightly before the consonant as well. (These are characteristics of the so-called "yetiv".) But take that positioning into account, and it becomes clear that it signifies not only a rhythmic prolonging of, but also a melodic marcato on, the accented syllable. In effect, as pashta's position at the end of a syllable signifies the forward prolonging of the "syllable time", so the position of mehuppakh/"yetiv" at the beginning of a syllable signifies the backwards prolonging of the "syllable time". So adjusted rhythmically, the melodic line in context gains a lively rhythmic nuancing that enables it to support the words with precision. It would be a simple matter to convey such precision by means of the timing of the gesture conducting the melody.

Updated December 27, 2011