Enneachord

But Aristoxenus calls the following foreign instruments — phœnices, and pectides, and magadides, and sambucæ, and triangles, and clepsiambi, and scindapsi, and the instrument called the enneachord or nine-stringed instrument.

The heptatonic system above must be radically segregated from an older model described in UET VII, 74, where the generative paradigm comes from an instrument fitted with nine strings, the enneachord, exposing the theory of a nine note system that is called enneatonism.

So Apollo's instrument, a sixteenth-century lira da braccio with nine strings like the Greek enneachord given over to the nine muses, serves as the culmination of the lyre's development, as pictured in the Parnassus by Raphael.

For while we are used to simply dividing modes internally in terms of fifths and fourths to make an octave, Jacques complicates matters for us by introducing concepts from the monochord in Liber V, thus enneachords and decachords, i. e., ranges of nine and ten notes. […] The sixth tone forms an enneachord (C-d) and does not contain a diapente under its proper ending, but rather (again) a semitritone.

These dynamical systems "pluck" the seventh chords out of the all-combinatorial enneachord in sc 9-12 (9 through 12).

He thinks of the creation as a grand symphony (see also figure 13), a notion we shall find diagrammed in figures 79-83; and here he explicates the universal harmony as ten "enneachords" — that is, a chord of nine notes.

If we agree that the system consisted of 2 consecutive descending heptachords, or two conjunct enneachords, then we have theory applied to a specific instrument rather than pure theory.

It should be noted that R. Dumbrill believes that, in view of the fact that there are nine strings, we should refer to this set of nine strings/notes as an “enneachord” (or as an “enneatonic” system, like “pentatonic” or “heptatonic”).