In light of the upcoming solar eclipse, I thought I’d do a quick dive into the last line of “Eclipse,” by Pink Floyd, the last song on Dark Side of the Moon:
And everything under the sun is in tune
but the sun is eclipsed by the moon
[This article is also available as a video.]
We call the side of the moon not visible from Earth the dark side, but during an eclipse the side we can see goes dark. Theoretically, there’s always a dark side anda lit side of the moon and the only meaningful difference during an eclipse is our perspective, based on our location.

The fact that there’s always a dark half, always a lit half, and that lit crescents are only a matter of perspective (meaning that varying degrees of crescents all exist simultaneously)… this tends to be lost on us, as we’re stuck in a daily perspective pause that divides the moon’s phases into separate events. So I wonder if our daily pausing of the phases of the moon is why the fermata in music, designating both a hold and a pause of a note or rest, is in the shape of a crescent moon surrounding a dot, as if attempting to eclipse a very tiny circular sun.

The Leading Tone blog describes it this way: “The fermata symbolized… the end of a completed phrase, where all the polyphonic lines would come together in stable consonance and hold there as one before beginning again… its appearance is in fact identical to the corona symbol of medieval lore… and is related to modern astronomical symbols for a solar eclipse.” As the holding of a note, the fermata is like a lunar interval, the span of time it takes the moon, paused in phase from our perspective, to pass from the prime meridian at Greenwich to any local meridian. It’s paused but moving at the same time.
Like the fermata, the star and crescent is an ancient symbol, appearing as early as 2000 B.C. on a relief of a Sumerian king. As I discussed in an earlier video, the Sumerian understanding of music was sophisticated, more so than that of the Greeks, and the Sumerians used Pythagorean musical values long before Pythagoras was even born.

The generation of notes on the Pythagorean Circle of Fifths is done by stacking 5ths, and 5ths are considered the “sol” position in the do-re-mi-fa-sol scale. When the 5th intervals begin to generate accidentals in the key of C, the sharps and flats or black keys on a piano, the frequencies become much more drilled down into complex decimals. These accidentals form the dark side of this circle, resembling a crescent moon adjusting or eclipsing early 5ths, the early sol or “sun” notes.

Like the sun’s noontime apex position at each meridian on the earth, the perfect 5th as sol is the central mese of the scale. But as Francis Bacon pointed out through a cipher in “New Atlantis,” the mese of the musical scale was usurped by the note of F#, something I discuss in Chapter 14 of The Next Octave.
In the harmonic key of C, the mese or sol, is a white key, the note of G on a piano. Its position as mese has been usurpsed by the accidental of F#, a black key on the piano, which all sounds very much like the lyrics at the end of “Eclipse.”


And this is how I see a large part of the tension between Roger Waters and David Gilmour. There’s a running joke in the world of popular music that Roger Waters can’t tune his own bass. In this video still from 1971, David Gilmour is adjusting one of Roger’s tuning pegs right in the middle of a performance.
But I’m not convinced that Waters can’t tune his bass. I think Waters won’t temper his bass.
Every now and then, I’ll use my phone’s tuning app on a Pink Floyd song when only one instrument is holding a note, presumably under the direction of some fermata, and I often get readings on Waters’ bass and Gilmour’s guitar that don’t mesh. Gilmour’s guitar is almost always playing an equally tempered frequency, or very close to it, and not always, but often I’ll find Waters playing a Pythagorean value. That means that, often, their instruments aren’t in tune with each other.
It’s possible that Waters tunes his bass by ear, which tends to produce intervals that are “just.” In fact, tuning by ear tends to produce Pythagorean intervals, and those would obviously clash with Gilmour’s equally tempered guitar.
The tuning app on my phone consistently gauges the first low E note of the song “Time” right around 81 Hz, a full 1 Hz lower than the equally tempered E at 82.4 Hz. That’s a difference perceptible by the ear. The next note from Waters’ bass is an F# that registers at 91 Hz, again more than one Hz lower than an equally tempered F# at 92.5. I’ve also recorded Gilmour playing an A at 110 Hz in the song “Time,” and that’s a precise, equally tempered A two octaves below A at 440.
As I’ve mentioned many times before, E at 81, like we hear Waters playing on “Time,” is a Pythagorean value, as dramatized in the Phantom of the Opera, where the Phantom represents harmonic tuning as set against the Pythagorean tuning of Christine Daae.
Is that why Andrew Lloyd Webber snagged the chromatic arpeggio of D to Bb from Pink Floyd’s song, “Echoes”?

When plotted on the Circle of Fifths, this chromatic arpeggio from D to Bb that’s played in both “Echoes” and the Phantom of the Opera theme song, produces a five-pointed star… a star and crescent.
If we shift the Circle of Fifths around so that the dark crescent is on the bottom, as it is in some occult symbology, we now have the note of D at the apex mese of the circle, looking very much like the central position of the scale as the Sumerians placed it in their ennead.


The song, “Beneath a Moonless Sky” tells us a lot about the relationship between the Phantom and Christine, or more precisely, between harmonic and Pythagorean tuning. The Phantom exists in a musical world without an eclipsing moon. He represents harmonic tuning and the accidentals of the harmonic scale produce no complex decimals. Neither are they generated in a group; they’re dispersed throughout the scale, in order, so there’s no cluster of black keys in this scale, no crescent shaped moon eclipsing the sol or sun. In the Phantom’s world, there’s no usurpation of the mese.

And on the night beneath a moonless sky, Christine was able to enter the world of the Phantom, leaving the crescent moon of Pythagorean tuning behind. Only Christine exists in a sky with a moon, as that moon is the crescent of accidentals on the Circle of Fifths. I find a lot of symbolism when the Phantom’s mask covers only the left side of his face. The left-side mask of the Phantom is his attempt to cover up his harmonic tuning and move into her world of the eclipsing crescent on the left side of the Circle of Fifths.

The Phantom of the Opera portrays the attempt to marry the powers of 2 and 3, but it was a romance that wasn’t to be. And whenever we see the moon eclipsing the sun in music, we know that Pythagorean tuning is expressing that conflict existing between the moon and the sun.

And this gives us a better understanding of the masonic pillars representing the sun and moon and the central letter G, the first perfect 5th off the harmonic tonic of C, in masonic symbolism.