You can get tricked in your answer so I'd like to elaborate for you. Everything above is true, - to be more specific, it depends where you live.
In the U.S., by law, if a whiskey is labelled "rye whiskey" it must contain at least 51% rye grain in it's mashbill (ground up grains).
In the U.S., a whiskey can contain alot of rye grain without having to be called such, (ie. not list that in it's labelling). To be labelled "bourbon" it must contain at least 51% corn, with the remainder often mostly rye and malted barley.
In the U.S., there is also a Rye whiskey that is made from 100% malted rye and as such is the only pure malt produced in the U.S. (Old Potrero)
in Canada, almost all Canadian Whisky is referred to as "rye whisky". However, Canadian whisky is almost always a blend of other distillates and flavourings, and most Canadian Whisky contains actually a very small portion of rye distillate (in Canada, it's mostly from corn) with some containing actually no rye whisky at all. Of course, there are exceptions.
So, if you are in the U.S. drinking a Canadian Whisky, is it really a "rye"?