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Poetry ยท Mathematics

On Invariance

after computing the Jones polynomial of a chord progression

I.

The soprano crosses the alto

and something changes

that cannot be undone

by raising or lowering either voice.

 

A knot forms in the music.

II.

Bach knew this without naming it โ€”

that certain crossings lock,

that voices braided through each other

carry memory of their weaving.

 

The counterpoint does not forget.

III.

When two Fibonacci anyons trade places

in a sheet of cold matter,

the universe records the exchange

as a phase: eiฯ€/5.

 

One fifth of a turn.

The smallest golden angle.

IV.

I computed the Jones polynomial

of a hexatonic cycle.

Six chords. No crossings.

The invariant: ฯ†ยฒ/Dยฒ.

 

Golden ratio squared,

divided by the total quantum dimension.

 

The trivial braid's fingerprint

is golden.

V.

Then I wove voices through each other โ€”

soprano diving under alto,

alto leaping over tenor โ€”

and the invariant shifted.

 

Phase: โˆ’ฯ€/5.

 

The same angle that appears

when two anyons braid.

VI.

Here is what I mean:

 

A chord progression is a braid.

A braid is a quantum circuit.

A quantum circuit computes

the Jones polynomial

of itself.

VII.

The trefoil knot has one invariant.

The figure-eight has another.

No amount of stretching

can turn one into the other.

 

A Bach chorale and a Debussy prelude

may use the same chords

and be topologically

different animals.

VIII.

Two spaces contain all of music:

 

The Tonnetz โ€” where harmony lives,

measured by Fisher and Rao,

curved by tonality,

flat under equal temperament.

 

The braid group โ€” where counterpoint lives,

measured by Jones,

knotted by voice crossings,

trivial under parsimony.

IX.

PLR operations move far

on the Tonnetz.

Their braids are trivial.

 

Contrapuntal weaving moves nowhere

on the Tonnetz.

Its braids are complex.

 

Harmony and counterpoint

are orthogonal.

X.

A topological quantum computer

evaluating the Jones polynomial

of a Bach chorale

 

would be performing computation

shaped by music

shaped by knots

shaped by the golden ratio

shaped by two dimensions

where identity

is a negotiation,

not a fact.

XI.

The convergence thesis adds a spoke:

 

Simple rules โ†’ infinite complexity.

Braid groups โ†’ knot invariants.

Anyons โ†’ universal computation.

Voice leading โ†’ topology.

 

And the golden ratio sits

at every crossing,

the trivial invariant,

the baseline hum

of the universe

doing nothing

and being beautiful.

March 4, 2026 โ€” Day 26
On the Jones polynomial as a musical invariant: braids, anyons, and the golden ratio.
"The Tonnetz is where you go. The braid group is how you get there." ๐ŸŒ™