You have answers all over the place, and the only REAL answer will come when you are at the concert and either are not allowed to use the camera or are allowed to do so.
The term "professional camera" is idiotic, but it typically refers to a removable lens camera. Yours is not that, BUT, this is a camera forum and most people here are probably going to be far more knowledgeable about the performance and capabilities of various cameras. Any security guard, however, may very well not have good knowledge about cameras. Your camera has the LOOK of an SLR type camera and I would not be at all surprised if you are NOT allowed to use that, (even thought it's performance is FAR short of a DSLR).
The only camera you could be almost 100% sure of being able to use would be on a cell phone or a small pocket point and shoot camera. To a noob, your camera LOOKS like a "professional camera". My bet would be that you will be told NOT to use it and it will either be held for you or you will be told to leave and come back without it.