Oops - let me clarify.
This was an overnight train with sleeper cars, plus a separate dining car, plus a separate lounge car with a bar. Not a commuter train or anything. Passengers had assigned seats only in the sleeper cars, rotated in-and-out of the dining car as scheduled for food, and stopped by the lounge car whenever they wanted to, um, lounge.
We played in the lounge car. When we started, the car was basically empty except for the bartender. He encouraged us to play. We asked him to tell us if ever we should stop. (He's the nice fellow standing in the pic.)
After playing just for him for around 20 minutes, we went to dinner. As we were leaving the dining car, some passengers asked "what's in that instrument case?" I answered "an ukulele." They asked us to perform for them and followed us into the lounge car. With the bartender's permission, we started up again, and the passengers sang along. Then some other passengers wandered in, made requests, and joined in, too. Then one of the train's conductors (?) with a great voice sang a Adele song.
Hope this clarifies things!