Instructions
Power on your Wii console and start up Rock Band as you normally would.
Go to the Main Menu and select "Options." On the Options menu, select "Calibrate System." You'll have the option to select your TV or manually calibrate the game. If you select your TV on this menu and still notice problems, manual calibration is for you.
Select "Manually Set" on the Calibrate System menu. Adjust the audio/video sync by moving a slider that will appear on the screen to the left and right. The goal is to get it so the icon on the screen goes through the target at the same time as a sound effect plays.
Adjust the lag compensation. By strumming the strum bar as an icon passes through the target in the center of the screen, you can change the frequency that information from your controller is sent to your console and when it receives it. Try automatically calibrating your system before attempting this, as it can be tricky.
Adjust the overscan option if there are black borders around your game screen. The overscan option will make the game appear bigger on the screen, filling out the extra space. For this option, all you have to do is check a box.