This interface is popular with 2-year-olds!
It's a remake of Chrome Music Lab's spectrogram interface, because I wanted to make a simple spectrogram interface that used Tone.js and where the code was beginner-friendly. In the end, Tone.js' own fast Fourier transform (FFT) method seems less precise than some others, so this interface uses an implementation by Vail Systems. Tone.js' UserMedia and Player classes are still used, however.
I hope you enjoyed experimenting with this example.
Feel free to get in touch if you have any questions or suggestions.