1. Make sure your sound volume isn't super-loud to start... Click the buttons or press keys on your keyboard. Change the volume or octave underneath the keyboard.
  2. In my (non-comprehensive) tests, this works well in desktop browsers and iOS. Sadly, it is not so great on Android - it works, but with more audio latency than ideal. As an Android user myself, this makes me sad, but my research suggests this is a typical issue with the WebAudio API implementation in Android browsers.
  3. Also, this was created for fun, without thorough testing. I present this "as is" with no warranties or promises of any kind.
  4. Have Fun!