tools

Drone Machine

A pure-tone drone in just intonation on C, so A4 sits at 436.05 Hz, 15.6¢ below A440. Choose a note from C through B and an octave from 1 to 5, then detune a twin oscillator by up to 8¢ to hear beats at the difference frequency. Add upper partials (2nd through 9th, plus the 11th, 13th, 16th and 21st) to build a harmonic field. Useful for ear training, tuning, and meditative listening.

Real-Time Spectrum Analyzer

Microphone input drawn two ways: a live spectrum on a log-frequency scale, and a spectrogram that scrolls through the last 8 seconds. Choose a root and dashed markers show where its harmonics fall, up to the 16th; the loudest peak is named as a partial with its distance in cents. Useful for microtonal ear training, tuning investigations, and understanding what your instrument is actually doing. Listens only, no audio output.

Harmonic Series Explorer

Twenty-four partials over any fundamental from 20 Hz to 4 kHz, each showing its distance from 12-TET in cents. Toggle individual partials on and off and hear how the timbre changes as you build or strip the harmonic structure. The math that underlies both timbre and just intonation, made audible.

Subharmonic Series

The mirror image of the harmonic series: each row sounds the root divided by n. Overtones stack a major triad and undertones a minor one, and two buttons play 4:5:6 above the root against 1/4:1/5:1/6 below it. Unlike overtones, undertones are not in the root's own sound, which is why the minor triad has long puzzled theorists looking for a "natural" basis in acoustics.

Sound Field

Press and drag a 55 Hz sawtooth through a resonant lowpass filter. Left to right sweeps the cutoff from 45 Hz to 18 kHz; higher up is louder and more resonant. Release to silence.

Wilson Combination Product Sets

Erv Wilson's hexany, dekany, and eikosany: pitch sets in which every tone is the product of two or three odd generators drawn from 1·3·5·7·9·11. Click to build chords inside these structures, or play a row of the set's own harmonic and subharmonic chords (the eikosany has 15 of each).

Phase Machine

Two voices, one pattern, A panned left and B right. Voice B drifts at a slightly different tempo, and new rhythms and melodies emerge from the collision; lock steps holds each new alignment for two passes, as in Piano Phase. A minimal compositional engine inspired by Steve Reich's phasing works.

Euclidean Rhythm Generator

Four layered rhythmic rings. E(n,k) distributes n pulses across k steps as evenly as possible, by the same algorithm that computes the GCD. One tap fills a layer with tresillo, cinquillo, bossa nova, samba, aksak or ruchenitza, and each layer rotates. A mathematical view of global rhythmic traditions.

Interval Figures

Every musical interval has a shape. Two sine tones at a ratio trace one curve, and the phase slider bends it: a unison runs from a diagonal line to a circle, an octave from a figure-eight to a parabola, a fifth weaves a knot. Whole-number ratios close into a stable figure; φ:1 never closes. Spin for a random ratio, keep the ones worth a scale, and play them back in order.