Molson Canadian is running a neat program this summer. Basically, if you volunteer to work on a park project (planting trees, improving trails and doing basic beautification like litter pick-up) you'll get a free concert ticket to a Red Leaf Project Concert. You have to be legal drinking age to take part, and of course, there's a limit of one concert ticket per park project volunteer.
You can get more details on Facebook or on this page from Molson (must be legal drinking age to view). You can find park project near you using their interactive map. There are 100 projects across Canada available, but each one has a set limit of participants, so sign up sooner rather than later if you're really interested in taking part.