TERRY TRILLA · SMART METRONOME
TerryTrilla — Metronome
A metronome that goes beyond 4/4 — 13 flamenco palos, up to three polyrhythmic layers, world rhythmic systems and a tempo trainer in one circular widget.
Rhythm is a closed loop
Most metronomes do one thing: count beats. They're useful. But if you play Bulería, study Balkan rhythms, or work on 3-against-4 polyrhythm — the standard tick-tock leaves you on your own.
The Terry Trilla Smart Metronome works differently. Rhythm here is not a linear scale running off to the right. A measure doesn't end on the last beat — it flows into the first beat of the next cycle. That's exactly how musicians who work with cyclic structures think: flamenco compás, Indian tala, Cuban clave.
How the beat wheel works
A circle divided into N equal sectors — one per beat. Inside, several layers of information operate simultaneously.
Outer ring of sectors
Each beat is a sector. Color and brightness reflect accent strength. Subdivisions — eighths, triplets, sixteenths, quintuplets, sextuplets — fill each sector. Real audible clicks, not just markers.
Three arc rings
Groupings (2+2+3 in 7/8), phrase structure (call-and-response, clave 3–2, fuerte and suave in Soleá) and an animated progress arc sweeping around the cycle in real time.
Pulse star at the center
Points = beats. Point length = accent strength. On each strike the current point extends 20% and fades in ~200 ms. Bulería and Soleá are two different stars, though both have 12 beats.
UNIQUE ARCHITECTURE
Clock Mode and Wheel Mode — two modes of one circle
Clock Mode — familiar meters
For 4/4, 3/4, 6/8, 12/8 — the circle keeps 12 reference points like a clock face. Familiar structure, but alive and animated.
Wheel Mode — non-standard meters
For 5/4, 7/8, 9/8, 11/8, 16-beat Tintal. The twelve markers disappear, the circle rebuilds into N equal sectors. Switching is automatic.
An architectural solution found in no known competitor.
Flamenco — 13 palos with built-in compases
Each preset is not just a tempo. It's a correct compás with proper accents, groupings and phrase structure. Bulería 12 places strong accents on beats 12, 3, 6, 8, 10 — exactly where they belong. Soleá is divided into fuerte and suave. Siguiriya delivers its characteristic asymmetric structure.
Alegría · Abandolaos · Bulería (6) · Bulería (12) · Bulería (variant) · Fandangos · Rumba · Sevillanas · Siguiriya · Soleá · Tanguillos · Tangos · Tientos
Polyrhythm — for those who have outgrown 4/4
Up to three independent rhythmic layers simultaneously — each with its own tempo ratio, timbre and volume. All synchronized via a mathematically correct master cycle. Cycles always close together; drift is impossible.
Layer 1 — primary
Green. The reference pulse every other layer locks to.
Layer 2 — secondary
Blue. Own beat count, own sound, own volume. Mute and solo independently.
Layer 3 — tertiary
Purple. Presets 2:3, 3:4, 4:3, 5:4, 3:2, 4:5 — one click away.
Training modes — the metronome as a practice tool
Speed Trainer
Gradual BPM acceleration from a starting value to a target, in defined steps. Typical: start at 60 BPM, add 5 every 45 seconds, target 144.
Bar Breaks
Silence every N bars. 4 on, 4 off, then back. Hold the tempo through the silence and return exactly on the beat. The classic internal-metronome exercise.
Random Drops
Random beat omissions at a set probability. At 30% you can't lean on every click — you hear and feel the rhythm instead of following it mechanically.
Professional-grade sound
60 FPS
Visualization via requestAnimationFrame. Zero lag with audio even under heavy browser load.
Microseconds
Web Audio API scheduling with look-ahead precision. Real professional accuracy.
9 sample categories
Classic click, drumkit, woodblock, palmas, cajón, darbuka, tabla, clave, electronic. Plus zero-latency synth clicks.
Swing 0–75%
From straight feel through triplet feel to hard shuffle. Applied to pairs, quadruplets and sextuplets.
The metronome inside TerryTrilla Circle
Smart Metronome is not a standalone application. It lives as one of the central modes of the Scale Circle widget — the same circular system where users explore scales, intervals, chords and instrument tuning.
The visual language is unified: the Scale Circle star and the metronome pulse star share the same principle — N points, point length equals intensity. The same vocabulary throughout. The user isn't learning a new interface — they're applying already-familiar logic to a new task.
Tuner, crystal, star and metronome — four equally-weighted central modes of a single widget. Music education is not split across different applications. It happens in one environment.
Who this metronome is for
Flamenco guitarist
Picks the Bulería preset, gets the correct 12-beat compás with palmas clara. The star shows structure at a glance — no need to count aloud.
Jazz drummer
Turns on 3-against-4 polyrhythm, assigns different timbres to layers, mutes the primary — checks whether the 3-beat figure holds without the main pulse.
Conservatory student
Sets 7/8 with grouping 2+2+3, sees three grouping arcs and seven star points, hears the accent on beat 5. Then switches to 2+3+2 and compares — by listening.
Music teacher
Enables Tintal (16 beats) for an Indian tala lesson. Wheel Mode opens the circle into 16 sectors, exports the preset as JSON, sends to the student.
Hobby guitarist
Sets 4/4, turns on Speed Trainer, works from 80 to 120 BPM. The metronome doesn't tick — it pulses. It feels different.
Composer
Writes a contemporary piece in 11/8 (3+3+3+2), saves the preset as JSON for the percussionist. Adds 5:4 polyrhythm to test how the section tracks it.
Technical specifications
| Parameter | Value |
|---|---|
| BPM range | 20–300 |
| Subdivisions | eighths, triplets, sixteenths, quintuplets, sextuplets |
| Swing | 0–75% |
| Time signatures | 4/4, 3/4, 6/8, 2/4, 5/4, 5/8, 7/8, 9/8, 11/8, 12/8, 16 and more |
| Flamenco presets | 13 palos |
| Polyrhythmic layers | up to 3 |
| Sound timbres | 9 sample categories + synthesized clicks |
| Visualization | 60 FPS via requestAnimationFrame |
| Audio precision | microseconds (Web Audio API) |
| Training modes | Speed Trainer, Bar Breaks, Random Drops |
| Keyboard shortcuts | Space (play/stop), T (tap tempo) |
| Mobile support | yes, touch controls |
| Themes | light and dark |
| Test coverage | 591 tests, 97% code coverage |
Frequently asked questions
A full-featured online metronome built into the Terry Trilla learning platform. It supports standard time signatures, 13 flamenco palos, polyrhythm up to three layers, and training modes. It visualizes rhythm as a closed loop rather than a linear scale.
A regular metronome counts beats. Smart Metronome shows rhythmic structure: groupings, phrases, accent strengths, subdivisions — all at once. For non-standard time signatures (7/8, 11/8, 5/4), the circle dynamically rebuilds into Wheel Mode.
13 palos: Alegría, Abandolaos, Bulería (6), Bulería (12), Bulería (variant), Fandangos, Rumba, Sevillanas, Siguiriya, Soleá, Tanguillos, Tangos, Tientos. Each with correct compases, accents and groupings.
Simultaneous sounding of multiple rhythmic patterns — for example, 3 against 4. Up to 3 independent layers with different timbres and volumes. Used in jazz, contemporary classical music, and West African ensemble rhythm.
Yes — three modes: Speed Trainer (gradual BPM acceleration), Bar Breaks (silencing for several bars to develop internal pulse), Random Drops (random beat omissions).
Yes. The widget is fully responsive, supports touch controls, keyboard shortcuts Space and T, and maintains precision through the Web Audio API.
Core features are free. Advanced capabilities — polyrhythm, extended presets, custom setlists — are available on PRO and ENTERPRISE plans.
Any preset can be saved as a JSON file and imported in one click. It contains BPM, time signature, accents, groupings, phrase structure and selected sound.
READY TO PRACTICE
Study scales. Practice in tempo. One environment.
Smart Metronome is part of the Terry Trilla platform — explore scales, chords and intervals in Scale Circle and practice them immediately at the right tempo.