Half-Life 2 Soundtrack: Every Track and Where It Plays

Half-Life 2 does not really have a theme tune. What it has is a set of short cues dropped into specific rooms, and if none of them is stuck in your head, that is the shape of the score rather than a failure of memory.

The numbers are checkable. Combine OverWiki's track listing numbers 66 music cues in the retail game, fired from 55 distinct tracks — 56 filenames, because one track, Hard Fought, is listed under two. Laid end to end at the lengths of those in-game files, the 66 cues come to 82 minutes and 9 seconds of music across the whole campaign.

This is the map of it: the album, the moment each track fires, and the parts of the album you never actually hear in the game.

The short version

The score is by Kelly Bailey, who was one of Valve's earliest employees and had already written and recorded every piece of music in the first Half-Life. Per Combine OverWiki, most of the Half-Life 2 track titles were named by Marc Laidlaw, the writer — which is why an album about an alien occupation is full of particle physics puns.

The album is 43 tracks. Valve put it on Steam as Half-Life 2 Soundtrack, app 323140, on September 24, 2014. Steam's own API reports it as free and attached to Half-Life 2 (app 220), so if you own the game you own the album.

All 43 album tracks, and where each one plays

Album order below, with the in-game moment taken from Combine OverWiki's track listing. Where a track plays twice in the campaign, both placements are listed. Track times are the ones printed on the Steam store page.

Two entries there are worth stopping on. Tau-9 has a documented failure case: the wiki notes it plays when you use the magnetic crane, but not if you enter the crane with the use key. And Hunter Down is fifteen seconds on the Steam listing, thirteen in the game files — a full album track that exists to cover the beat after the last Strider drops.

The seven album tracks that are not what you heard

Thirty-six of the 43 album tracks map to a moment in the campaign. The other seven do not, and they split into two different kinds of not-in-the-game.

Four are music that plays nowhere in the retail game.

Three are album mixes of cues that do play, in a different edit. In each case the track name is familiar; the version on the album is not the version in the game.

• Hazardous Environments (1) is the long version of the Valve theme. The game plays a 35-second edit of it, in Kleiner's lab when you first put on the HEV suit.
• Pulse Phase (7) is described by the wiki as a portion of Dark Energy slowed down and pitched down. The in-game Pulse Phase is a different file, built from a short loop repeated four times, and it plays in "Follow Freeman!" and again in the Citadel elevator down to Breen.
• Tracking Device (34) is a CD-only mix. A different remix under the same name plays over the second section of the credits.

How much music each chapter actually gets

Cue counts and total length by chapter, in campaign order. Entanglement gets its own row here, though Combine OverWiki numbers it Chapter 9a rather than a chapter in its own right. Length is the sum of Combine OverWiki's times for the in-game audio files, which run a second or two shorter than the album times in the table above — so the two tables will not reconcile to the same seconds. A cue that gets interrupted still counts its full length here, so treat this as the ceiling, not what your ears got.

The cue numbering is strictly chronological, which is a useful check on the whole table: Point Insertion holds cues 1–3, Route Kanal 8–16, Anticitizen One 44–51, and the credits close it out at 65–66, with no gaps and no number used twice.

Two things fall out of that. Route Kanal and Anticitizen One carry the most music — nine cues and eight — and they finish within six seconds of each other on total length, 9:52 against 9:58. Both are long, linear, combat-dense stretches.

And Ravenholm is scored thinly — four cues, 3 minutes 46 seconds, less than half of what Route Kanal gets. Of the fourteen chapter rows above, only three get less: Nova Prospekt at 2:34, Black Mesa East at 3:41 and Dark Energy at 1:25. The credits are lower still at 2:34, but the credits are not a chapter. The horror chapter does its work in silence.

A third of it is Half-Life 1 with new names

Of the 55 tracks behind those 66 cues, 20 carry HL1_ filenames — music from the first Half-Life, reused in the sequel. Those 20 files account for 22 of the 66 cue placements.

Twelve of them have a documented original title, and the renames are the fun part of the album:

Read that column pair and Laidlaw's naming pass becomes obvious. "Drums and Riffs" is what a composer calls a file. "Tau-9" is what a novelist calls it.

That accounts for 12 of the 20. Five more are the short stingers — HL1_stinger_song7, 8, 16, 27 and 28 — credited to Half-Life but carrying no original title in the listing. The last three are remixes rather than straight lifts: Hazardous Environments is the trimmed Valve theme, Tracking Device is a remix of Half-Life's Credits/Closing Theme, and Triple Entanglement is Sirens in the Distance slowed down with the opening sirens cut. Twelve, five and three.

Two of the renames also land the joke on the room they play in. Black Mesa Inbound is the first chapter of Half-Life, and in Half-Life 2 the track plays in Eli's scrapyard where you meet Dog and get the gravity gun — the chapter that is Half-Life 2's own re-introduction. And Negative Pressure plays under Breen's speech in the Citadel.

Where to get it

The Steam listing is the simple route. It appears in your library like any other item, and the store page lists 149 MB of storage for the standard download plus an additional 278 MB if you take the high-quality audio option.

The streaming route exists because Valve partnered with the independent label Ipecac Recordings, which announced on March 16, 2020 that it was releasing soundtracks to four games in the Half-Life series to streaming services. The Half-Life 2 album there is the same 43 tracks in the same order.

The third route is the completist one, and it is the only one that gets you the cues that are not on the album at all — the ambient loops, the stingers, and files like Entanglement (loop), an eight-second .wav that the wiki notes is the only track in the game that plays as an ambient sound rather than as music. If you want the wider story of what else did not survive to retail, the cut content guide covers the rest of it.

Two older routes are worth knowing about and no longer worth chasing. The limited Half-Life 2 "Gold" package shipped a CD soundtrack with several exclusive tracks, and per Combine OverWiki the album — minus the CD versions of tracks 1 and 34 — was also dropped into the game directory of both the full and demo Audiosurf releases on Steam, as part of that game's Orange Box Soundtrack.

The runtime numbers do not agree

Two official listings, two totals — and one of them disagrees with itself.

Add up the 43 track times printed on the Steam store page and you get 61 minutes 56 seconds. Add up Spotify's own 43 track times, same album, same order, and you get 60 minutes 18 seconds. The header at the top of that same Spotify page says the album is "about 55 min", which the 43 durations printed directly underneath it do not support.

The Steam-versus-Spotify gap is not a different master. It is rounding, one track at a time: Steam's printed time is longer than Spotify's on all 43 tracks, by between one and four seconds each, and those 43 small differences are the 1 minute 38 seconds between the two totals.

So the two defensible numbers are 60:18 from Spotify's per-track data and 61:56 from Steam's printed times; the "about 55 min" header is not one of them. If you want a figure nobody argues with, quote the track count — 43 is the number on the Steam page, on Spotify, and in Combine OverWiki's OST numbering.

Quick Action Checklist

• The soundtrack is free on Steam as app 323140 if you already own Half-Life 2.
• 43 tracks on the album; 36 of them play somewhere in the campaign.
• Four album tracks — Miscount Detected, Headhumper, Combine Harvester, Biozeminade Fragment — play nowhere in the retail game.
• Three more are album-only mixes of cues that do play: Hazardous Environments, Pulse Phase, Tracking Device.
• 66 cues fire across the campaign, from 55 distinct tracks, totalling 82:09 at full in-game file length.
• 20 of those 55 tracks came from Half-Life 1.
• Route Kanal has the most cues of any chapter at nine; Anticitizen One has the most minutes at 9:58. Ravenholm has one of the smallest allowances.
• For the cues that never made the album, extract hl2_sound_misc_dir.vpk from your install.