In the past it was said by Kevin that the songs were always in the perspective of the announcer.
In Elena's songs about Samantha they have said multiple times that the voices call her the 'Chosen one' and now it says here that the sound of a lullaby is calling him the 'Chosen one'. Also when it says 'Shadow, nothing, all I am" these are answers to the two riddles in "Abracadavre" where Samantha says she is a shadow and then nothing.
It also says multiple times that 'I need your carrion', Carrion being dead flesh. In the Easter egg Richtofen needs the dead flesh from the zombies, and the zombies are out to die to make the announcer stronger. This is stated by Samantha in moon. Both singers also say 'I'm undone', this would obviously be Richtofen describing himself in Aether, the same way Samantha did.
