Which songs does the pack replace?

Only the vocal versions of the Killing Floor 2 songs. You switch between the KF2 and KF1 tracks by toggling the vocals option in the main menu.

Can I go back to the original music?

Yes, if you back up the original .wem files before overwriting them. Copy them back to restore the stock soundtrack.

Mods & Workshop

KF2 Mod: Play KF1 Soundtrack in Killing Floor 2

This community mod lets you hear the classic Killing Floor 1 soundtrack inside Killing Floor 2. It does not add new menu entries: it replaces only the vocal versions of the KF2 songs, so you flip between KF2 and KF1 music simply by enabling or disabling the vocals option in the main menu. The guide was published in English and Spanish. If you like the KF1 atmosphere also read Killing Floor 2 OST and soundtrack and audio design.

Killing Floor 2 gameplay with the replaced music Killing Floor 2 in a fight: the replacement affects the battle tracks that play with vocals enabled.

Installation

Download the KF1 Soundpack archive (the author posted it on Dropbox) and open the folder of the tracks you want.
Extract the .wem files to Steam\steamapps\common\killingfloor2\KFGame\BrewedPC\WwiseAudio\Windows.
Confirm the overwrite. Back up the original .wem files first if you want to restore them later.
Start the game and enable vocal songs in the main menu.

A second gameplay screenshot from the guide Another in-game screenshot from the guide.

Tracks replaced

The pack covers battle, main menu, boss and lobby/trader music.

Battle music: Dirge tracks (Defective, Disunion, Repulse), KF_Connections, KF_My_AK, KF_Soldiers, Watching, Chillbumps, Bled Dry, Burst Nova, Click Click Click, Containment Breach, Creature in the Straw, Defection, Ground Finale, Harm Intended, Hunger, Jolly Invader, Launch Sequence, Organ Grinder, Neurotoxin, Overpressure, Pathogen, Smiles and Laughter, Some Assembly Required, Southern Dismemberment, Split Wig Shinding, Stilt Walker, Story Time, Surface Tension, Terror-Go-Round, Thrills, Spills of Entrails, Treatments are more Profitable than Cures, Unrelenting Horde, Witness Prevention, What Dwells in Toyland?
Main menu: Outbreak.
Boss: Abandon v3, Abandon All.
Lobby and trader: KF_Abient_Asylum, KF_Abient_Asylum_Returns, Drifting Through the Bodies, Hush Little Ones (midnight comes), Insect Wings, Locomortuis, O Terrorbaum, Sin Soma and the Masquerade, Smolder, Storytime, The Carnivalous Waltz, The Derelict, The Edge of the Abyss, The Stitches are a reminder, Vapour, Wading Through the Bodies.

Credits

All credit for the music goes to zYnthetic. The remix, extension and mash-up work was done by the original author, AnOldLady. Source: Steam community guide "KF2 & KF1 Songs [EN] / [ES]" by Sir Alfred.

FAQ

Which songs does the pack replace?: Only the vocal versions of the Killing Floor 2 songs. You switch between the KF2 and KF1 tracks by toggling the vocals option in the main menu.
Can I go back to the original music?: Yes, if you back up the original .wem files before overwriting them. Copy them back to restore the stock soundtrack.