Things You'll Need
Instructions
Load "Rock Band Unplugged" to the main menu on your PSP.
Highlight "Music Store" and press "X." Sign in to your PlayStation Network account if prompted.
Highlight a song you wish to purchase. Press "X." Most songs are $1.99, but some may be 99 cents or free. "Rock Band Unplugged" uses the same network as the rest of the "Rock Band" series, giving you over 1,000 different songs from which you can make a selection.
Select "Purchase" from the list. It will automatically download to your system, and the game will automatically recognize and load the song into the library.
Select "Quickplay" from the main menu, or select "Career Mode" followed by the location of your tour. Select the song you just downloaded to play it. This will be within the list of songs already in the game, not its own separate section. For example, if you just downloaded "Still Alive" and have your setlist organized by song name, you can find it in the "S" category with all of the other songs.