I think it was set in a desert sort of place, or maybe a very grey town, or something.
I think it was something to do with limbo, purgatory that kind of thing
People arrived on a bus
They couldn't leave
The main character found a way out by, breaking through a wall, digging through it, a tunnel, something, into a country house, or kitchen, or bakery, something like that.
It had to be kept a secret that he was digging.
Eventually people found out I think.
There might have been some "bringing of the outside in", maybe was sneaking baked goods "down", damn I'm grasping here.
This might be the clincher, I think the character started digging out the wall because they could hear music through the wall. Something about music. Maybe there wasn't music in the place or something.
Crazy I know, but it's been doing my head in for ages trying to remember this damn movie.