Should not be a problem - NAFTA is good for US musicians/callers, but bad for Canadian ones. Few restrictions that I know of unless you're going to make thousands of dollars. In any case, I usually just say that I'm going to perform for a folk dance in a church basement and they tend to lose interest very quickly...

One caveat to this is that there are some restrictions - or at least used to be - for DJs trying to come into Canada to perform. If you're planning a techno contra event, for instance, you might not want to mention that. I once rented DJ in Canada to avoid that hassle at the border. 

Chuck