Guitar Hero: World Tour was the first title in the Guitar Hero franchise to incorporate different band instruments, including drums and vocals. However, getting your peripherals all to work can be a little bit on the challenging side, especially when you are trying to use a microphone, as you will need both your mic and a controller to be connected for the microphone to work.
Plug your microphone in to the PS3 before you turn it on. The microphone should have a USB cord, which will fit into one of the four USB ports on the front of the PS3. Guitar Hero: World Tour does not support wireless mics.
Turn on the PS3. Hold down the PS button on your PlayStation controller to boot up the system and then log in and start the game. The controller you are using will be tied to the microphone and will be used to set individual difficulty settings for the vocalist player.
Plug in any other band peripherals you plan on using. During the game's main screen, make sure to plug in any guitar or drum peripherals that other players will be using during the game. Once all instruments have been connected, press start.
Select game mode and difficulty using your controller. Use your controller to select the song and vocal-specific difficulty. Keep in mind that the PlayStation controller is tied to the vocals, as the guitar and drum peripherals each have their own selection inputs.
If you are having trouble with your microphone, ensure that it is connected snugly in the PS3s USB port and try restarting the console. If the microphone still doesn't work, it may be incompatible with the game or need to be replaced.