Mostly this problem is contained in the fact that the US makes it so difficult for Canadians to get green cards (you heard it here), but if an American orchestra really wants a player, they have their ways.
“Fortunately, President Kennedy and Robert Kennedy disagreed with the estimate and chose a course of action less ambitious and aggressive than recommended by their advisers.”
“I found my niche as a character actor, and I've never felt like a movie star or teen idol and never wanted to.”