This example uses the Web Audio API to play two sawtooth tones a major third apart, each triggered sequentially after a one-second pause. The code converts MIDI note numbers to frequencies using a mathematical formula, then creates and starts an oscillator through an AudioContext. Oscillator lifecycle events schedule the second note, while a biquad filter is instantiated but not connected. The page itself displays only a static message, with styling handled by CSS and no D3 visualization logic present despite the D3 library being loaded.