Instructions
Unravel the cord on the microphone. The "Rock Band" microphone is shipped with its cord so tightly tied that it cannot be used to play the game until it is untangled.
Insert the USB side of the microphone into a USB slot on the front of the Xbox 360. Any USB slot on the Xbox 360 will work.
Connect a Xbox 360 controller to the system. The Rock Band microphone cannot be used unless a controller is connected to the system as well.
Load the "Rock Band" game. If the microphone was properly connected, a microphone icon will be displayed in the game menu. The microphone is now hooked up and can be immediately used to play the game.