Each of the zombies maps in Call of Duty: Black Ops 4 has a hidden Easter egg song hidden within it that you can trigger by completing a set of requirements along the way. We’ve already shown you how to find the secret songs in the three base maps, but what about Classified? Here’s everything you need to know to trigger the secret song in Classified for Black Ops 4 zombies.

How to Unlock the Easter Egg Song in Classified

We’ve already walked you through how to unlock the secret song in IX as well as both Blood of the Dead and Voyage of Despair. Unlocking the secret song in Classified is a bit easier to accomplish, though you’ll still need to find a couple of items to trigger the song. The items in question are three vodka bottles, all of which can be found by exploring the map in Classified. The good news is, we’ve taken the guesswork out of finding them and we’ve included the location of each bottle below.

Each bottle will trigger a dinging noise when it is activated, letting you know that you’ve properly triggered it.

Bottle #1

The first bottle that we’re going to go looking for can be found inside of Central Filing. This bottle can be found on top of one of the filing cabinets—it’s pretty hard to miss—so look around the center area of filing cabinets until you spot the bottle standing upright on the cabinet. Walk up to it and interact with it to trigger the noise.

Botte #2

To find the next bottle on our list you’re going to need to take the elevator down and head over to the War Room. Continue down to the lower level. From the stairs, follow the wall to the second control panel and go prone. You should see this vodka bottle laying sideways on the floor. Interact with it and listen for the ding to trigger it.

Bottle #3

The final bottle that you need to find and trigger is going to be found over in the labs area. Make your way to North Laboratories and then head into Procine Research. The bottle can be found in the back left-hand corner of the room. Look for it nestled on a shelf underneath the counter in the back corner.

With all three bottles located and triggered, the song should begin to play. Sit back, enjoy and start blasting away at the zombies that flood into the map.

Now that you know how to trigger the secret song in Classified, head back over to our Black Ops 4 guides for more helpful information about the game.