Johnny Cash's Rusty Cage Easter Egg Song Tutorial:
#1 Go into the library next to where you spawn in-game, go towards the corner of the room between both the windows and look on the bookshelve for a bottle shaped object. Hold the action button whilst facing the item, do this for the next three locations
#2 Go up to the infirmary and in the room in which the bath tubs are look opposite at the table and you should be able to see the second bottle leaning against the wall.
#2 Head down to the docks and to the gate in which can be unlocked with the wardens key, whilst facing it follow the fence/wall to the left of it, eventually you will notice the bottle behind a stack of crates.
Kevin Sherwoods 'Where are we going' Easter Egg Song Tutorial:
Wardens Key Is Required!
#1 Head down to the Citadel tunnels.
#2 Follow the spiral to the bottom and unlock the fencing over the digital display.
#3 Go back to the top and enter afterlife using the electricity box, head back down and input the number "935".
Kevin Sherwoods 'Samantha's Lullaby' East Egg Song Tutorial:
#1 Do not revive yourself as soon as you begin the game, this will then start the song played in the background. (Multiplayer Only)
Regards C-Nathan