T.H.I.R.I.

Harmonic Series • Arbitrary Octave Divisions • Analogue Bass • Stereo Tape Delay

Sacred Geometry Microtonal Lab

Explore continuous overtone geometries across any custom division ($N = 2 \dots 64$), shape an analogue bass synthesizer directly under the graph, groove with a 1-lane 4/4 drum sequencer, and sculpt cascading echoes with stereo tape delay.

Want the same harmony engine in your own code? Get a free API key.

MICROTONAL GEOMETRY ENGINE N = 16 DIVISIONS
MCP HARMONIC BRIDGE Inject AI Model Context chord root → retunes geometry, scale ratios & bass monosynth:
→ MCP Protocol Docs
SACRED GEOMETRY PROJECTION
Assigned to Step
Degree 0
Ratio: 1/1 • 0.0 cents
Click to play & assign to selected step.
THIRI ANALOGUE BASS VOICE MONOSYNTH
ROOT PITCH: 65.4 Hz (C2)
1. OSCILLATOR WAVE & OCT
OCT:
2. FILTER (VCF) 24dB LOWPASS
Cutoff: 340 Hz
Res (Q): 3.8
Env Mod: 65%
3. ENVELOPE (VCA) ATTACK / DECAY
Attack: 8 ms
Decay: 320 ms
Drive (Saturation): 45% Warm
4. OUTPUT & TEMPO VOL & BPM
Bass Volume: 85%
Tempo (BPM): 136 BPM
4/4 BASS DRUM SEQUENCER (16 Steps • Click pad: Root → 5th → Octave → Rest)
QUICK BEAT:
Octave Divisions (N) 16 Steps
Custom Divisions (2–64): 16
Division Mathematics SCALE METHOD
Selected Node / Step Pitch Degree 0 / 16
Unison (1/1)
Frequency: 130.81 Hz
Exact Cents
0.0¢
Ratio / Factor
1.0000
Closest 12-TET Note: C (0.0¢)
Binaural Entrainment HUD Δf: 6.2 Hz (THETA)
Theta Waves (θ) 4.0 – 8.0 Hz

Deep restorative meditation, REM trance, somatic neural synchronization.

THIRI Live Telemetry REAL-TIME RAIL
// Ready: Click drum pads to sequence 4/4 bass, tweak delay, or hit Space to Play
00:00.0
EXPORT:
HARDWARE MIDI:
INPUT MODE:
MIDI: Ready (or use computer keys A–L)
Fundamental (f₀): 130.8 Hz
Master Tempo: 136 BPM
Arp Gate / Decay: 85%
Reverb Blend: 48% Wet
Delay Echo: 35% Wet
DIRECTION:
PRESET:
ARP TIMBRE:
REVERB SPACE:
ARP VOL: 75%
STEREO TAPE DELAY MODULE 1/8D (Dotted 8th • 331ms)
SYNC:
Feedback (Repeats): 45%
TONE:
Delay Mix: 35% Wet
TARGET:
16-Step Arpeggio Pattern (Upper Harmonic Cloud • Click step to edit) STEP: -
EDITING STEP 1: Degree 0 (130.81 Hz)
Degree Slider:

Microtonal Acoustics & Sacred Geometry

The Freedom to Divide the Acoustic Octave

Beyond the 12-TET Paradigm

Western music settled on 12 divisions because $2^{7/12} \approx 1.4983$, which is tantalizingly close to the pure Pythagorean fifth of $3/2 = 1.5000$. But 12-TET is only one coordinate in an infinite universe of pitch systems.

By dialing the octave into custom divisions ($N$), you can experience historic and exotic acoustic realms: 19-EDO provides virtually pure major thirds; 22-EDO unlocks the microtonal shruti system of Indian classical rāgas; 31-EDO mirrors Christiaan Huygens' 17th-century equal meantone; and 53-EDO resolves the Pythagorean comma to within 0.07 cents.

Integer Harmonics vs. Equal Divisions

When you choose Integer Harmonics ($N \to 2N$), the interval ladder is formed by standing wave physics: $f_k = f_0 \times \frac{N + k}{N}$. At $N = 16$, you access the pure overtone ladder with no frequency beating.

When you choose Equal Division ($N$-EDO), the octave is mathematically partitioned logarithmically: $f_k = f_0 \times 2^{k/N}$, allowing transpositional symmetry. THIRI unifies both models, calculating ground-truth frequencies in Hz so generative AI agents and musicians can produce microtonal works with mathematical rigor.