Can you get three native Russians to sing the Volga Boatman Song, merge them together, and then play them when someone's in a riverboat on Stalingrad? That would be so awesome. You'd need to extend the Volga though, which I'm sure you're doing anyway cough cough.
Damnit Kasperle. I keep finding myself staring and laughing at your avatar! In other news...I think your boat song could be done. Couldn't you place the little sound-box thing in the boat, kinda like you place it in the radio model? That way when the boat goes it plays. I'm pretty sure you can since EoD had that "FLight of the Valkrie" song in the Medi-vac chopper.