I can't think of the right choice of words but basically a song that appears to be in the same universe as another song from a different artist.
Like just before or after an event mentioned in a song or from a different perspective.
Can't think of a particular song combo but as an example one song is about a murder, the other is asking for forgiveness and it seems it's the killer from the first again.
Lets say Maybe Green Days basketcase doesn't get better and becomes hostile and so becomes the protagonist of Pumped up Kicks.
Anyone have any other suggestions of songs like this?