If you haven’t seen it, you should check out the video of 3 random guys in a shopping mall in Texas who start to make music together:
https://www.youtube.com/watch?v=cUFVR5sgbt0
The way they improvise together is beautiful; it will surely make your day. Today, 4 days after the video was posted to Youtube, it has already been watched over 9 million times. Go check it out, and enjoy!