This music is for STEALTH-ONLY heists like the Shadow Raid.
I know that Payday 2 players cannot read, but please try!
A Hat in Time, the "cute as heck platformer", has a phenomenal soundtrack including quite a few atmospheric tracks, especially in the stealth-oriented missions. Some tracks get more intense as you approach your objective, which is pretty much how stealth heist music works in Payday 2. The music is in OGG format, ripped straight from the game files with Umodel.
I couldn't get it working without using CustomOST unlike the regular heist tracks (in fact, I couldn't even get the stealth tracks mods from this site to work unless they're on CustomOST, but perhaps I'm missing something), so CustomOST is required.
Update: I've added BeardLib versions which kinda work, but only if have the Music Volume Mixer mod and play the tracks in the pre-planning menu first. It is important that you do not click away to your loadout or something. Look, it's better than having your game randomly crash by using CustomOST which is sadly no longer supported.
The tracks in question are:
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(BeardLib only) Mafia Town Time Rift, PoNR is Collapsing Rift
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A Forsaken Place
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Battle of the Birds Time Rift, PoNR is Collapsing Rift
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Dead Bird Studios: Reception/Closed, Sneaking Theme Normal/Western, Basement/Security Breach; PoNR is Collapsing Rift again
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Murder on the Owl Express, Who Dun It, Tick Tock; PoNR is Train Rush
