A Musico-theosophical Point
The traditional names of the notes of the musical scale were first canonized around 1000 AD by Guido d'Arezzo, who invented a staff notation that was a precursor to our Western musical notation. He was charged by the Pope to standardize the music used in Catholic liturgy, which had diverged into many different practices in different locales. His scale was: Ut Re Mi Fa Sol La. He gave a mnemonic for this scale based on the first stanza of a hymn sung in the Divine Office on June 24, the feast of John the Baptist. It goes:
Ut queant laxis
which translates as:
So that these your servants can, with all their voice, sing your wonderful feats, clean the blemish of our spotted lips, O Saint John!
In this hymn, which was probably written by d'Arezzo himself, each line except the last starts on the scale note whose name is its first two letters. Note that d'Arezzo's scale starts on G below middle C, which was known as Gamma in a Greek system of notation; hence his sequence of notes is know as gam-ut, and the scale itself is called "gam".
Later, around 1600, the theorist Giovanni Doni changed Ut to Do, and added Si which d'Arezzo did not recognize as a scale tone, named from the initials of the the above hymn's last line. His scale was understood to be in descending order of tones. He mnemonicized the names as abbreviations of these Latin words (mnemonicization was a favorite trope since ancient times of the "method of symbols", in which one series of things is theosophically associated with another, thereby enriching both for the mind's contemplation):
Do - Dominus, Lord, i.e. God
Si - Sider, star, i.e. all galaxies
La - Lactae, milk, our Milky Way galaxy
So - Sol, Sun
Fa - Fata, fate. Fate is ruled by the planets, hence Fa is the planets.
Mi - Microcosmos, the small universe, the Earth.
Re - Regina Coeli, Queen of the Heavens, the Moon.
Do - Dominus
Occultists and alchemists of the 17th century used this series of names of scale notes as a cosmic symbol. This is the form that was adopted by Gurdjieff and transmitted to us by Ouspensky. It represents the Ray of Creation.
Now, Microcosmos is also Man, who is the image of God, "as above, so below". This is the meaning of Mi in the lateral octave. We have this diagram in In Search of the Miraculous:
Fa So La
In the cosmic octave, Mi is the Earth. In the lateral octave, Mi is Man. Mi can be read as "me" in a play on words. Fa So La is "organic life", which fills the gap between "earth" and "the planets", allowing the planets to act on human "fate", Fa, through La and So in the lateral octave. What do these notes Fa, So and La “mean”? Fa is bloody life, involved in its universal fate of living and dying, eating and being eaten, reproducing and spreading, changing and developing new forms through the Darwinian battle for survival; So is the heart, the innocence, of life; La is the "song" of life, its beauty, its incipient transcendence of mere organic nature.
Si (lateral octave) is especially interesting—in the diagram, its place is parallel with Fa (cosmic octave) in the diagram, so the relationship between the two would musically speaking be the diabolus in musica, the tritone (i.e. the three whole tone steps between the four notes Fa-So-La-Si). Somehow the harmonious interval that exists between the Sun, So (cosmic octave) and Do (lateral octave), the Absolute for Man, becomes diminished and dis-harmonized as it descends through the Do-Si interval. It changes from God to The Devil, the fallen god, who then inherits the responsibility of transmitting higher influences to organic life and eventually to man. He (the Devil) does this by tempting man through the Dominant Seventh chord (So Si Re Fa), which contains the Diabolus, and which man must resist by resolving to the Tonic chord (Do Mi So). In this process, Si (the Devil) ascends back to Do (God) and becomes the root upon which the chord of man is built; Re (the moon in man—see Beelzebub’s Tales to His Grandson) quickens and ascends to become Mi (man himself), while Fa (Fate) descends upon Mi, man, who, as the mediant, the middle term, must simply accept it; So (life's innocence, whose purity was obscured by the dissonance with Fa, fate) simply remains in place and becomes the crown of the triad.