Being our first time in Paris, one novel thing about this journey was the number of people coming up looking for money (handouts) on the train. They would either:
i) play the accordian whilst looking around for those passengers who were giving them eye-contact, and then target these passengers for money after their musical piece had finished; or
ii) go up and down the carriage with a young child, handing out a card explaining their circumstances, and then come back round looking for donations (and the return of their card).
They would tend to move up the carriages, one following the other. I did feel rather guilty and so did give one of them some money.
Have a great time!