From GameWatcher: “Dead by Daylight is not just an asynchronous multiplayer title where one supernatural murderer attempts to slaughter four survivors. The game has got several layers of meta-game features, one of which are so-called addons.
Dead by Daylight Frank’s Mixtape is one particular addon which adds a special additional effect to the skill that it is equipped on. Since addons tend to drastically change how a murderer plays, you’re definitely going to want to look into how they work.”
Source: N4G PC Dead by Daylight Frank's Mixtape – What is It, and How to Get One?