For a few years now it's become popular to place pianos in public places anyone can use. You never know who will show up
Below are a only a few I've come across on YouTube. Hope you enjoy them.
Munich- Nicola Tenini (16 years old)
Henri Herbert, keyboard player with the Jim Jones Revue (a high octane rock and roll band from London), gives an impromptu performance on the concourse of St Pancras International station, London
Like I said you never know who'll show up.