§ Frequency · An instrument for curiosity
Wave Lab
Wave 1
Nearest note at A = 432 Hz: A4 exactly
Harmonics · click to add or remove
A sine is this stack of harmonics; removing one changes the shape on the scope. Switch to Custom to set every level by hand.
Harmonic levels
Explanation
The scope
The oscilloscope draws your sound over time. Each wave appears faintly in its own color, and the bold blue line is all of them added together. Choose how many cycles to show; the corner tells you how much real time that is.
Harmonics make the shape
A sine is one single frequency. Square, triangle, and sawtooth waves are really stacks of harmonics - extra waves at 2×, 3×, 4× the base frequency - which is why changing the shape changes the picture. The H buttons switch individual harmonics on and off, and the sliders set how loud each one is. Choose Custom and those sliders become the shape itself. That is additive synthesis: building any repeating wave out of harmonics.
The analyzer
Turn on the analyzer to see the same sound by frequency instead of time. The blue curve is measured from the combined signal; the colored lines show where each wave’s harmonics land. Move across it to read any frequency, or click a peak for its details.
Frequency and tuning
Every wave starts at 432 Hz. You can type any frequency you like, and the note buttons follow whatever you set concert A to, so nothing here locks you to a standard pitch.
Sound and sharing
Sound stays off until you turn it on, and plays only the parts inside hearing range. Your whole setup lives in the page address, so copy the link to save it or send it to someone.