SWING ARC — Visual Motion Metronome

Quick Start

1

Choose a starting point. Select a click pattern, or try a FEEL preset for a ready-made combination of settings.

2

Set the tempo. Use TEMPO or TAP. Long-press the BPM readout to enter a value directly.

3

Choose how to see the rhythm. Select ARC, WAVE, CAT, or CIRCLE, then press START.

4

Explore. Adjust SWING and OFFSET while it plays and notice how the same rhythm can feel different.

FEEL

FEEL presets combine click pattern, swing, accent, and OFFSET settings into practical starting points for exploring how different timing relationships feel. They are not definitions of a genre; players, styles, and contexts may organize these relationships differently. The preset positions are, however, informed by the timing framework behind SWING ARC.

Learn more about the musical theory behind SWING ARC →

The Idea Behind SWING ARC

SWING ARC is a visual metronome that represents the time between Beats as continuous motion.

During development, I began experimenting with OFFSET: keeping the Beat and Subdivision timing the same while shifting their temporal relationship to the continuous motion.

A Simple Pattern

At certain OFFSET positions, a very simple timing structure appeared.

With straight eighth notes:

Beat → midpoint → Subdivision → midpoint → next Beat

These positions are evenly spaced.

Expressed as phase:

0° → 90° → 180° → 270° → 360°

In SWING ARC, two representative positions appear in the straight case: −25% and −75%.

These are not two different rules.

−25% corresponds to the midpoint on the Beat → Subdivision side.

−75% corresponds to the midpoint on the Subdivision → next Beat side.

So even with the same Beat and Subdivision timing, different candidate OFFSET positions appear depending on which side of the timing relationship is treated as the reference for the continuous motion.

This does not mean that 90°, 270°, −25%, or −75% have been proven to be naturally special positions for human rhythm perception.

They appear simply because the neighboring timing intervals are being divided in half.

What Changes with Swing?

Things become more interesting when Swing is introduced.

Swing moves the Subdivision.

If the important feature were a fixed phase such as 90° or 270°, the preferred position should stay in the same place.

But if the important feature is the relationship between the Beat and Subdivision, then the midpoint should move with the Subdivision.

For the Subdivision → next Beat side, for example:

Straight eighth: Subdivision at 50% → midpoint at 75%
Triplet swing: 66.7% → 83.3%
Swing at 75%: 75% → 87.5%

This gives a simple testable prediction: if the reference is relational rather than fixed, changing Swing should move the relevant position.

Different Rhythms, Different Relationships

There may also be more than one useful Subdivision–Beat relationship within a rhythm.

In sixteenth-note grooves, for example, the most relevant relationship may sometimes involve the last Subdivision before the next Beat.

With 60% sixteenth-note Swing, that final Subdivision falls at about 80% of the Beat interval, placing its midpoint with the next Beat at 90%.

This is the current candidate position used for the Second Line FEEL preset.

With straight sixteenth notes, the final Subdivision falls at 75%, giving a midpoint of 87.5%. This is the current candidate used for the Funk preset.

These are not intended as definitions of Funk, Second Line, Jazz, or any other musical tradition.

They are working hypotheses generated by the model.

The Idea in One Sentence

The central idea is simpler:

People may organize musical time not only around discrete Beats and Subdivisions, but also around relative timing positions within continuous motion.

What About Body Movement?

The same question may apply to body movement.

When you walk, what moment do you actually experience as the rhythmic reference?

The instant the foot touches the ground?

The moment it leaves the ground?

The highest or lowest point of the body?

Even at the same tempo, rhythm may be experienced differently depending on which part of the movement cycle is being used as the reference.

What We Know — and What We Don’t

Existing research on rhythm, coordination, entrainment, continuous movement, and anticipatory timing is broadly compatible with this possibility.

But it does not yet establish that the specific midpoint positions predicted by SWING ARC are perceptually or physically important.

SWING ARC is not claiming that groove has been reduced to mathematics.

It is not claiming that a particular OFFSET defines a genre.

And it is not claiming that mathematical midpoints automatically become meaningful perceptual states.

The claim is much smaller:

During development, a simple and testable timing relationship appeared.

SWING ARC provides a way to see it, move it, and experience it directly.

Whether that relationship turns out to have broader perceptual, bodily, or musical significance is still an open question.

CAT MODES

STEP
Clear stepping and body movement make the rhythmic structure easy to follow.

GROOVY
Emphasizes the larger motion and flow of the groove, with more relaxed upper-body movement.

DANCER
A more choreography-focused dance with varied steps, gestures and body movement.

DRUMMER
Shows the rhythmic pattern most directly through the playing motion.

CONDUCTOR
Uses larger, conducting-like gestures to shape the overall motion. At 0% OFFSET, it works as a straightforward conducting motion and should be easy to follow. At the special OFFSET positions, it becomes more experimental: it may be difficult to lock into, though some players may find a stable relationship between the larger motion and the beat.

Beta Notes

For the tightest audio/visual relationship, device speakers or wired audio are recommended. Bluetooth and other wireless outputs can add latency; use Wireless A/V Sync in Advanced when needed.

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BUILD ID: DOMAIN-STATS-DUAL-HOST-OFFICIAL

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