As a new artist, you come out, and there are so many other new artists. It seems like there's a whole wave of new artists that come along every year. In '05, I was part of the crop. It was a lot harder trying to set myself apart from the rest of the pack.
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.

