This article has yet to be cleaned up to a higher standard of quality.
You can help by correcting spelling and grammar, removing factual errors and rewriting sections to ensure they are clear and concise. Visit our Cleanup Project for more details.
Kelly Bailey composed numerous short pieces of original incidental music that are interspersed throughout Half-Life 2. Several tracks from the Half-Life soundtrack were re-titled and carried over, while some were remixed.
The limited-edition Half-Life 2 "Gold" package included, among other exclusive extras, a CD soundtrack. Although the CD contained several exclusive tracks, it did not include all of the music used in the game.
In-game, energetic techno tracks tend to back significant battles, atmospheric synthesizer pieces enhance key plot and exploration moments and reinforce feelings of adventure, isolation, or melancholy in the player.
|1||Hazardous Environments||01:24||"A Red Letter Day": when Gordon puts on the H.E.V. Suit.|
|2||CP Violation||01:45||Route Kanal: as Gordon avoids being hit by the Razor Trains.|
|3||The Innsbruck Experiment||01:07||Route Kanal: when first fighting Metrocops wielding MP7.|
|4||Brane Scan||01:40||Anticitizen One: during the fight in the generator plaza.|
|5||Dark Energy||01:32|| Highway 17: when Gordon leaves Shorepoint Base in the Scout Car.
Dark Energy: during the first half of the credits.
|6||Requiem for Ravenholm||00:33||"We Don't Go To Ravenholm...": when Father Grigori bids farewell.|
|7||Pulse Phase||01:09|| "Follow Freeman!": during the Strider battle outside the Nexus.
Dark Energy: when Gordon descends in the elevator to face Breen.
|8||Ravenholm Reprise||00:52||"We Don't Go To Ravenholm...": when Gordon enters Ravenholm.|
|9||Probably Not A Problem||01:26||Route Kanal: during the Headcrab Shelling to Station 6.|
|10||Calabi-Yau Model||01:46|| Sandtraps: when Gordon enters the Vortigaunt Camp.
"Follow Freeman!": in the building surrounded by Overwatch Snipers.
|11||Slow Light||00:44||Highway 17: after Gordon defeats the Gunship at New Little Odessa.|
|12||Apprehension and Evasion||02:17|| "A Red Letter Day": after Gordon uses the Crowbar for the first time.
Sandtraps: during Gordon's raid to the bunkers on The Coast.
|13||Hunter Down||00:15||"Follow Freeman!": after Gordon kills the last Strider before proceeding to the horse.|
|14||Our Resurrected Teleport||01:11||"A Red Letter Day": when Gordon enters the Teleporter room in Kleiner's lab.|
|15||Miscount Detected||00:48||Exclusive to the Soundtrack release.|
|16||Headhumper||00:08||Exclusive to the Soundtrack release.|
|17||Triage At Dawn||00:45||"We Don't Go To Ravenholm...": when the battle in the garage is over.|
|18||Combine Harvester||01:25||Exclusive to the Soundtrack release.|
|19||Lab Practicum||02:54||Highway 17: when Gordon passes under the bridge.|
|20||Nova Prospekt||01:57||Nova Prospekt: as Gordon enters the cell blocks.|
|21||Broken Symmetry||01:03||Route Kanal: after Gordon leaves the sewers.|
|22||LG Orbifold||02:52||"Follow Freeman!": after Gordon is instructed to go to the horse.|
|23||Kaon||01:11||"Follow Freeman!": when Gordon fights the Combine Gunship on the Overwatch Nexus.|
|24||You're Not Supposed to Be Here||02:41||Water Hazard: after receiving the mounted gun for the Airboat.|
|25||Suppression Field||00:55||Anticitizen One: as Gordon finds his first Squad in the playground.|
|26||Hard Fought||01:15||Anticitizen One: during fights with Civil Protection, while assaulting a barricade and the underground shoot-out while waiting for a hole to be blown open by a rebel.|
|27||Particle Ghost||01:40||"We Don't Go To Ravenholm...": after Gordon leaves the Ravenholm Mines.|
|28||Shadows Fore and Aft||01:26||Point Insertion: during the G-Man's speech.|
|29||Neutrino Trap||01:35||Our Benefactors: as Gordon exits the sewer tunnel at the base of the Citadel.|
|30||Zero Point Energy Field||01:41||Route Kanal: when Gordon enters the sewers after the Hunter-Chopper attacks.|
|31||Echoes of a Resonance Cascade||01:38||Anticitizen One: upon entering the toxic underground tunnel.|
|32||Black Mesa Inbound||02:13||Black Mesa East: when Gordon and Alyx enter the scrapyard at Black Mesa East.|
|33||Xen Relay||00:39||Dark Energy: upon Gordon's arrival to Breen's office.|
|34||Tracking Device||01:03||Dark Energy: during the the second half of the credits.|
|35||Singularity||01:19||Entanglement: upon Gordon's arrival to the Nova Prospekt teleporter.|
|36||Dirac Shore||01:26||Entanglement: when Gordon enters the Depot's flooded basement.|
|37||Escape Array||01:26||Black Mesa East: as Gordon nears the dam's Electrical Station.|
|38||Negative Pressure||01:57||Our Benefactors: as Gordon leaves the combine elevator.|
|39||Tau-9||02:05||Highway 17: when Gordon enters the crane to move the Scout Car.|
|40||Something Secret Steers Us||02:02||Sandtraps: during the Dropship attacks at Lighthouse Point.|
|41||Triple Entanglement||01:32||Anticitizen One: when Gordon enters the sewers after Alyx is captured.|
|42||Biozeminade Fragment||00:32||Exclusive to the Soundtrack release.|
|43||Lambda Core||01:44||Water Hazard: as Gordon flees from the second Hunter-Chopper.|
|44||Entanglement||00:39|| Nova Prospekt: Upon entering the Combine Wall crushing canyon at end of chapter, just before meeting Alyx.
Route Kanal: At the beginning of the chapter, when the player is on the stairs waiting for the train to jump, if the player quick saves and then loads, this track will play. It may be a hint that Valve wanted this track to play on that part, but it was cut.
|45||Highway 17||00:59||Sandtraps: In a house just outside the zombie-infested tunnel, where a few Rollermines also break in an attempt to attack Gordon.|
|46||A Red Letter Day||00:29||A Red Letter Day: upon entering Kleiner's lab for the first time.|
|47||Sand Traps||00:35||Sandtraps: When driving through the tunnel full of zombies.|
|48||CP Violation (Remix)||01:43||Route Kanal: Upon leaving the pool with a mixer in it, where Civil Protection proceed to roll explosive barrels at the player.|
|49||Train Station 1||01:30||Point Insertion: This music plays just outside the City 17 Trainstation, when seeing City 17 for the first time.|
|50||Train Station 2||01:12|| Point Insertion: Plays when being chased in the rooftops.
Follow Freeman: Plays when seeing a dropship from the Overwatch Nexus.
|51||Radio||00:40||Anticitizen One: Plays while the TV with G-Man on it is turned on.|
- Bailey's affinity for wordplay is evident in his track titles, as they often reference real world subjects as well as in-game facts:
- Triage at Dawn references the same situation the player finds himself at the point it is played; Triage of Winston at dawn break.
- LG Orbifold is a theoretical physics geometry term mentioned by Dr. Kleiner while checking teleporter parameters moments before teleporting Alyx.
- Zero Point Energy Field is a reference to the Zero Point Energy Field Manipulator.
- Xen Relay is a reference to Dr. Mossman's speech about how they control a Xen Relay.
- Tracking Device is a reference to the fact that the HECU and the Combine have been using the tracking device in Freeman's HEV suit to easily track and ambush him.
- Something Secret Steers Us is taken from the Vortigaunts quote "Something secret steers us both. We shall not name it."
- Tau-9 is a reference to the Tau Cannon present in the Scout Car.
- CP Violation is a violation of charge conjugation parity symmetry) in particle physics.
- Many of the songs on the Soundtrack are either remixes or simple name changes of songs from the Half-Life Soundtrack:
- Hazardous Environments is a renaming of Valve Theme (Extended).
- Zero Point Energy Field is a renaming of Cavern Ambience.
- Lambda Core is a remix of Diabolical Adrenaline Guitar.
- Black Mesa Inbound is a renaming of Vague Voices.
- Singularity is a renaming of Traveling Through Limbo.
- Echoes of a Resonance Cascade is a renaming of Space Ocean.
- Tracking Device is a remix of Credits / Closing Theme.
- Biozeminade Fragment is a remix of Alien Shock.
- Something Secret Steers Us is a renaming of Nuclear Mission Jam.
- Pulse Phase is actually a truncated version of Dark Energy, slowed down by 50%.
- Radio is composed of two samples that come from the 1995 sample library Cuckooland: Ghost in the Machine from Zero-G, composed by Ian Sanderson and Simon Mills. The first one is called Distorted Trumpets, while the second one, whose pitch has been raised, is called Is that the Door?