Halo music on High Ground

This is an Easter Egg for the map High Ground that appeared in the Halo 3 Beta and Halo 3, that was changed slightly in the Halo 3 version.

Halo 3 Beta
To produce the egg in the Halo 3 Beta, create a party of four in matchmaking and enter the 2v2 playlist, or produce a custom game. Make sure that none of the players have the intent of actually killing each other, so you won't have the annoyance of enemies shooting you while trying to reproduce the egg. Keep vetoing maps until you find a game in High Ground. In the Base, there is a room with two large computer systems that can be destroyed. Next to the larger one (near the door which leads to the bridge to the pipe room) there is a small green box. Upon closer examination with a Sniper Rifle scope, you can see that it is a radio. You may be lucky and get the egg the first time, but you may have to try multiple times. Take out an Assault Rifle and shoot the small group of 4 silver circles on the right side of the green colored screen. If shot just right, the radio will stop hissing static and play what sounds like the song from Halo: Combat Evolved, Under The Cover Of Night. Otherwise, it will start playing something much more likely to happen, a message in morse code. The message says 'Frog Blast The Vent Core!' This is a phrase which explosive human simulacrums would say in another Bungie game, Marathon.

Halo 3
In the full version of Halo 3, the egg is much easier to hear. To hear the music, all you need to do is wait for a while in the computer room. The radio below the larger computer will eventually stop making static and morse code and will play random Halo songs (Halo 1, 2, or 3). You can tell it is about to play a song when it sounds like an FM radio just barely out of tune from a local station. Note, in Forge mode you can pick up the radio and place it in a different location, and it will still play music. This egg can been heard on flag games also if a player has guarded the base flag long enough.