This is fine in the US. Many engineering programs will happily accept kids who are really good at Physics and Math, also at least very good at other core academic subjects, and then having other interests like piano can really be a plus.
Of course you might want to have some sort of explanation of your interest in engineering, and actually I think it is good advice to see if you can do something where you get to see real engineers at work as a way of confirming your interest. But you do not need engineering-specific courses or competitions or so on.
But as others have suggestedâif your only concern was getting a good engineering degree, maybe Toronto is just not possible for a US college, any US college, to really beat. This happens in the US a lot too. If you are a resident of Michigan and are interested in engineering, it is really hard to beat going to Michigan. Same with California, and many other states.
On the other hand, if you want to actually get an engineering degree in four years and study music . . . that is not an easy combination, but as noted it is actually at least possible at Rochester, because of how their curriculum is set up. Same with Brown. My understanding is some people also do this at RPI, Case, WUSTL, and Lehigh.