One of the many techniques that Vonnegut uses in this novel to explore the horror of war is inserting himself as a character into the novel through a framing device at the beginning, and then every now and again popping up as a minor character in the novel. What this does is to juxtapose the somewhat extraordinary experiences of Billy Pilgrim alongside the reality of ex-soldiers who fought in the Second World War such as Vonnegut himself, and this gives Pilgrim's account added reality through the added focus that a first-hand narrative of somebody who was involved in the war and fought in it gives. Note the following quote from the beginning of the novel, when Vonnegut writes to Sam, his publisher, and apologises for the short and confused nature of the manuscript he is sending:
It is so short and jumbled and jangled, Sam, because there is nothing intelligent to say about a massacre. Everybody is supposed to be dead, to never say anything or want anything ever again. Everything is supposed to be very quiet after a massacre, and it always is, except for the birds. And what do the birds say? All there is to say about a massacre, things like “Poo-tee-weet?”
There is an irony in this quote, as if there is "nothing intelligent" to write about a massacre, then it is clear that Vonnegut has achieved a considerable feat in writing a whole novel about it. At the same time, there is a link established between the birdsong in this quote and the novel as a whole, as the sound of the bird becomes a repeated refrain throughout the novel, and is used to end the novel itself. Perhaps the novel is itself like the sound of birdsong after the terror of a massacre: something that merely shows that life continues to exist in one form or another, even though the silence that occurs after a massacre seems to represent the shock and horror of war and the difficulties that humans have in trying to live in such an environment. It is no wonder that Pilgrim's consciousness becomes fractured and his understanding of time and free will becomes so disrupted. The pressures of war as recorded in this novel would unhinge anybody. The framing device and the insertion of the novelist as a character into the novel itself therefore adds authenticity to Pilgrim's account as he struggles to find his way in the world and in particular to process his wartime experiences.