tool 01
The ratios are physics. The anchor is a choice.
what are ratios?
In just intonation, musical interval are defined by frequency ratios. For example a perfect fifth is always 3:2 — meaning the higher note vibrates exactly 1.5× faster than the lower. These ratios come from the harmonic series, a natural acoustic phenomenon in which vibrating bodies produce overtones. That´s why they feel especially "in tune". But tuning systems are still human choices.
about A=440 Hz
The pitch standard A440 (pitch standard)—where the note A above middle C is tuned to 440 Hz—has not always been universal. Historically, pitch levels varied widely between regions, ensembles, and time periods. As musicologist Fanny Gribenski documents in Tuning the World (2023), it became the global norm only after an international conference in 1939 — a specific institutional decision, made by specific people, with geopolitical weight behind it. Musical traditions across Asia, Africa, and the Middle East have long operated with their own reference points. A=440 is is a widely adopted convention. Not a law. This tool starts at 432 Hz.
how to use
Drag the slider or tap a preset to set your reference pitch. Tap any interval to hear it. All Hz values update live.
reference pitch
just major scale
extended / microtonal
tool 02
Three tools for questioning what your ear has been taught to hear.
exercise 01
Interval Library
Ten intervals from traditions outside equal temperament. Each one has a name, a home, and a reason for existing.
exercise 02
Drone Drift
A drone begins. At some point it slowly drifts. Press the button when something feels unstable.
exercise 03
In Tune?
Does it sound in tune or out of tune? Then see where it comes from.
You heard all 10 intervals.
Want to go deeper? Get the free listening guide with 3 key concepts, a tuning primer and Tracks to untrain your ear.
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