Diophantine Harmony

A playground for one sentence. The sentence has two halves. The page shows that the two halves do not depend on each other.

Harmony is a Diophantine condition between k·g and log2 of the primes. Nobility is a condition on the continued fraction of g itself. The two are independent.

I wrote this sentence on 2026-10-14, after GOLD-002. That experiment showed that every generator is within one cent of some golden generator at complexity 60, because the golden generators are dense. So the statement "Erv's generator is near a golden one" has no content at that depth. The sentence above is what survives. On this page the harmony half is amber, the nobility half is violet, and the generator chain is teal.

station 1

One generator, two readouts

Select a generator g. The circle is one octave. The amber marks are the targets: 1200·log2(p), folded into the octave. The teal dots are the chain: k·g for each k from −K to K. The harmony question is: for each target, does a chain dot fall within ε of it? The nobility question is: what is the continued fraction of g/1200? Change the targets and see which readout changes.

The presets are the Wilsonic lattices. The last button moves the targets to random positions. The violet readout does not change.

Diophantine readout (harmony)

targetcentsbest kerrorwithin ε

Continued-fraction readout (nobility)

station 2

The landscape

The landscape shows every generator from 0 to 600 cents. The amber line is the worst error over the targets, with |k| ≤ K, on a log scale. The dips are where harmony is possible. The shaded bands are the survival segments, where the worst error is less than ε. The violet ticks are the golden generators with complexity up to Q. Move the targets to random positions and the dips move. The ticks do not move, because they depend on g only.

worst target errorper-target errorsurvival segment (≤ ε)golden tick

Click the landscape to send that generator to station 1. The table below lists the segments. GOLD-003 tests this question: does a segment contain a golden generator of complexity ≤ Q more often than a random segment of the same width?

segment (cents)widthworst errorgolden inside (complexity ≤ Q)
station 3

Independence, as a cloud

The cloud shows 2000 random generators. The horizontal axis is the distance from each generator to the nearest golden generator of complexity ≤ Q, in cents. The vertical axis is the worst target error with |k| ≤ K. If nobility predicted harmony, the cloud would tilt. The page shows the correlation below the chart. The large violet points are the golden generators. The amber squares are the CPSFIT-003 count winners on the hexany, EG4 and the dekany.

What I think the sentence means

The harmony half. A generator chain plays the just interval p/q when some integer multiple of the generator falls within the tolerance of 1200·log2(p/q), modulo the octave. This is a simultaneous inhomogeneous Diophantine approximation. One real number g must approximate several fixed real targets with small integer multipliers. The multipliers are the val. The primes set the targets. This condition does not refer to the continued fraction of g.

The nobility half. A noble number has a continued fraction that ends in ones only. This makes it the hardest kind of number to approximate with rationals. The same property has three musical consequences. Its MOS ladder grows as slowly as possible. Every level has a large-to-small step ratio near φ. The Gral keyboard of its chain keeps the same cell shape at every depth. All of this concerns g and the rationals. None of it concerns the primes.

Why there is no mechanism. Move the targets and the dips in station 2 move. The ticks stay. No equation takes the continued fraction of g and returns the distance from k·g to log2 3. GOLD-002 measured the consequence. At complexity 60 the golden generators are about one cent apart, so every generator is near one. The near generators fit triads no better than the far generators.

What Erv did, on this reading. A triad-optimal generator is a survival segment. The segment is the full interval of g over which the kept triads stay within tolerance. Harmony cannot choose a point inside the segment. So the choice inside the segment is free. A golden generator inside the segment gives the melodic properties at no harmonic cost. The testable statement is this: the golden generator lies inside the segment. The statement "the optimum is within one cent of a golden generator" has no content at depth, because the golden generators are dense. GOLD-003 arm A found two of Erv's shallow golden generators inside count-optimal segments, at 317.170 and 503.786 cents. The expected number by chance was 0.24. This is a hint. The independence described above is the reason it cannot be more than a hint.

For Wilsonic. The generator-family selector is an aesthetic choice. The "golden" setting should do this: select the golden generator inside the survival segment when one exists. When none exists, it should show the triad cost of a move out of the segment. The setting must not act as a harmonic filter.