Guinness World Record for the longest melody played by model train. 9:00 video.
https://www.youtube.com/watch?v=aBNHmUT3GPg
Previously:
https://www.homemadetools.net/forum/...795#post100050
https://www.homemadetools.net/forum/...626#post128488
https://www.homemadetools.net/forum/...953#post160345