(Loved Trope) When the part of the OST actually exists within the game/anime/whatever else

I don't really have anything else to say, I just love this one

Also just to mention, it must be an OST made for the whatever piece of media the OST is in

Examples: - Devil Trigger (Devil May Cry 5): Literally plays in the opening scene of the game - Torture Dance (JJBA: Golden Wind): Idk the actual song name - Entire Katana Zero OST (Katana Zero): Best showcased at Club Neon where Hit The Floor (The theme that plays in the level) has a reverb to it - Karaoke Songs (Yakuza): It would only make sense that they exist in-game considering the karaoke minigame exists