Instructions
Professional Songs
Select the "Music Store" option from the game's main menu.
Select the "Store" option. The game will immediately display a list of all songs that are available to download.
Scroll through the list of available songs and highlight a song that you would like to download. Note that the professional songs cost money, so be sure to check the price before deciding to download one.
Click the "Buy" button.
Click "Confirm." This will purchase the song, which will begin downloading immediately.
Custom Songs
Open the "Music Studio" from the "Guitar Hero: World Tour" main menu.
Load the "GHTunes" menu.
Browse the list of available songs and select one that you would like to download.
Click the "Save" button to download the song that you want. The download will start immediately, and the song can be played as soon as the download is finished. All of the custom songs are free, so you can download as many as you would like.