A demonstration should be available here.
It simply listens to audio input, and then scans the transcript for certain keywords which trigger responses from an array. Built using vanilla JS, HTML and CSS.
By default there is a song in this folder called 'song.mp3'. Telling NVN.AI to 'play a song' will trigger playback. There is intentionally no way to stop the audio, except by refreshing the page.
You can replace song.mp3 with whatever song you like and it will play it.
There is a help option. If you say 'help', or a phrase containing it, NVN.AI will bring up a window listing some things you can try.