This is an idea whose time has come, but unfortunately no park has really persued it, except for Darien Lake, NY. (Six Flags). There is big money in concerts these days, and people who come for the concert would also spend money at the park. I spend many more of my leisure days at rock concerts than at amusement parks, and I often forego the parks to go see concerts I want to see. If some forward thinking executives (like those at CP?) would try it (and discover that it could be profitable), they are reaching a segment of people who otherwise would not go to the park.
There are two reasons concerts at parks may not work. First, most of the revenue from ticket sales goes to the artist. The venue makes money on food and drink sales, parking, and so forth. If the park isn't getting a significant portion of the ticket dollar, the park gets less return on the investment. Second, parks do not like the element that rock bands bring. Parks are typically "family oriented" and would not want to tarnish thier image. There are other artists/genres they could book, but that wouldn't be as much fun! I attended a Tubes concert at SFGam (then Marriott's) and it made for a fun day - I may have hand picked a different band, though.
I'd book the String Cheese Incident, and get a suite at the Breakers.