Twelve TheoryMath + Music Playground

Explore interactive music theory and music by numbers through Free Play, Math Mode, Chord Game, the Note Stage, Circle Counting, the Triad Chart, Church Modes, Harmonic Cone, Frequency Chart, Harmonic Wave, Waveforms, Harmonic Polygons, Tuning String, Sheet Music, Musical Circles, and Ear Training.

Interactive module

Frequency chart

Turn exact frequencies into visible intervals, chords, and inversions.

Starting octave
A2
Frequency system
Tuning reference
Starting frequency10 · A2108 HzEvery row uses an exact ratio from this starting frequency.
StartA2108 Hz
ResultE3162 Hz
1–12Note / moveRatioFrequency
Octave 1A2 → A3+108 Hz
Octave 2A3 → A4+216 Hz
Octave 3A4 → A5+432 Hz

Tap any frequency row to hear it.

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