This interactive visualization presents a two-octave piano keyboard rendered in SVG, with each white key colored in a distinct pastel rainbow hue. Users click individual keys to trigger a short synthesized sine wave tone, created through the Web Audio API's `createOscillator` and `createGain` nodes. Pressed keys temporarily darken via CSS transitions and React's `useState`, visually confirming the note selection. The layout maps 24 notes (C1 through B2) to specific frequencies, displaying numeric solfège labels on each key.