Concerned Ape (Stardew Valley): I swear on the honor of my family name, i will never charge money for a DLC or update for as long as I live. Screencap this and shame me if I ever violate this oath.
Uhh... I guess it's not technically DLC, but ConcernedApe is selling the game soundtrack for $5 on Steam. It's in the game's DLC category, but unlike some other soundtracks on Steam, it's not dependent on owning the base game to purchase.
But it's also downloadable content, so it is DLC... I guess it depends on how you want to define DLC nowadays.
DLC in this context is pretty widely understood to mean in game content. So additional areas, cosmetics, missions, etc. not the soundtrack. Steam just categorizes the soundtracks as DLC for games in general.