Every note hides others inside it. Pluck a string at 220 Hz and a quieter 440 Hz rings with it, and a quieter 660 Hz, and so on — the integer multiples of the fundamental.
Click anywhere to drop a fundamental. Watch its first eight overtones rise above it as ghost circles, each ringing for a moment before fading. This is what the inside of a single note looks like.
Higher click = higher pitch. Lower amplitude for higher harmonics, the way real strings actually sound.