Call of Duty: Black Ops Hidden Songs

Five: Don’t Back Down song

Locate the three red rotary phones throughout the Pentagon that ring and flash. The first phone can be found when you first start, after opening a set of doors in the corner. The second phone is on the catwalk circling the room after leaving the first elevator. The third phone is in one of the rooms after leaving the second elevator on the floor that the power is on. You can find the phones by following their ringing. Look at the phone, then hold [Action] until you hear a busy signal. After the third phone is accessed, the song “Don’t Back Down” by Eminem will play.

Kino der Toten: 115 song

Find the three meteors. The first meteor is located on a pedestal in a corner behind the soda in the main lobby. The second meteor is on a pedestal in the dressing room near some mannequins. The third meteor is the room upstairs near the alleyway, on a “dresser” with black marquee letters. Note: The meteors appear as red veined rocks. Hold [Use] on each meteor until your character says something or the veins in the rock glow red. After all three are found, the song “115″ by Elena Siegman will play.

Nuketown: Sympathy for the Devil song

(my personal favorite)
On the level “Nuketown”, shoot the heads off all the mannequins as fast as you possibly can to hear “Sympathy For the Devil” by the Rolling Stones.