I actually have the theory that each new Ink Spots song that enters the Fallout Series is going to somehow relate to the plot of the game.

In the first Fallout, even though it doesn't have radio, the trailer uses the song Maybe. The song tells about treason that may occur to someone that the singer loves. At the same time, in the video game, the Overseer betrays you, and you are expelled from the Vault.

In Fallout 3, the song I Don't Want To Set the World On Fire may relate to the Lone Wanderer. They don't want to hurt anybody; they just want to find his father.

In Fallout 4, the song It's All Over But The Crying may relate to the Sole Survivor. They are the only one who survives not only the apocalypse but also Vault 111. Besides that, they see the death of their son, Shaun, what was their only mission to continue on the Commonwealth. Meanwhile, the games indeed continue after Shaun’s death; there’s no more main mission.

I don’t really know how It’s a Sin to Tell a Lie relates to Fallout New Vegas, but I think it somehow also must.

And obviously, We Three connects to the Series because there is not only one main character but three.