If you do not activate the DLC, the songs will not appear in-game.
Copy the .pkg file and the exdata folder (if you have one) to the root of the internal hard drive ( /dev_hdd0/ ). rocksmith 2014 ps3 dlc pkg install
Rocksmith 2014 DLC is region-locked. The DLC you install must strictly match the region of your base Rocksmith 2014 game disc or digital installation. If they do not match, the game will ignore the new songs. If you do not activate the DLC, the