I think he means that every venue is different, and every seat is different also. The flash has a maximum range, and by adjusting to +1 or +2 you can help make it reach further, but only works if you're still relatively close.
If you find that your images come out blurry, I would try the sports mode. It tries to use a faster shutter speed to "stop the action". By using a faster shutter speed, the camera will compensate by opening the aperture more if possible, or by using a higher ISO. You'll have to experiment a bunch of photos before you get the best one.
I would turn on the Image Stabilization on your camera just to be safe, but probably the biggest factor will be how fast the band moves on stage, not how much you shake. If the entire picture comes out blurry, it's because of your shake, but if only one or multiple band members come out blurry, but the rest of the image is fine, then it's the people moving too fast. Either tell them to slow down, or use a faster shutter speed
Your camera has a Maximum Aperture of f/3.1 (W) - f/5.9 (T). That means that on the wide side of the lens (when you zoom out), the lens will let in more light and let you use a faster shutter speed and/or lower ISO. So if the pictures come out too blurry (too slow shutter speed) or too grainy (too low ISO), then you need to zoom out to use a larger aperture. (a large aperture is denoted by a smaller number, so f/3.1 is wider than f/5.9).
And most important of all, enjoy the show!