Perhaps, like birdsong, the book merely serves as a simple communication demonstrating that life still exists in a devastated world.
The bird’s inquisitive refrain returns in the very last line of the novel,
leaving us with the unanswered question of what life is like in the aftermath
of war. The birds sing regardless, not concerned about Billy’s plight, whether
good or bad. It could be said that they are an indicator of the indifference of
nature to man’s fate—a symbol of there being “no why.”

While the symbol of the barbershop quartet only
appears a few times in the novel, it serves as an important link between the
two worlds that Billy inhabits, the one where he is “stuck” and the one where
he is “unstuck”. Billy knows that this group causes an emotional trigger but he
cannot quite place their meaning in his life. They first appear on the plane
then they reappear later on in the text when they trigger Billy’s memory. This
moment is in chapter eight, at the anniversary party, and it is arguably one of
the most important scenes in the novel. Billy realises that the Barbershop
Quartet resembles the four German soldiers standing together in the
slaughterhouse during the Dresden bombing. However, Vonnegut writes that “Billy
did not travel in time” at this moment, instead he made the connection between
the Barbershop Quartet and the soldiers through memory.1
This is interesting since Vonnegut claims that the memory faculty is of little
use to him in writing the novel, as Vonnegut cannot remember many experiences
from the war.  Despite suffering
tremendous emotional anguish at both the sight of the barbershop quartet and
the memories that flooded back, this is one of Billy’s sanest moments, and for
the first time he stays rooted in the present. The singing provides Billy with
a long delayed catharsis for the tragedy he observed in the slaughterhouse, and
this is the first time he demonstrates self-awareness and opens up about his
experiences.

Vonneut emphasizes his refusal to stick to literary conventions in Slaughterhouse-Five,
as the novel is full of metatexual instances. In hospital, Rosewater introduces
Billy to the obscure science fiction writings of Kilgore Trout. It can be said
that Trout is yet another disguise for the omniscient narrator in Slaughterhouse-Five, much like the
Tralfamadorians. His novels make an impression on Rosewater
and Billy more than other books in that they offer an insight into an alternate
world. Indeed, Rosewater claims that The Brothers Karamazov contains everything
one ought to know about life, but the book “isn’t enough anymore”.2
For Billy and Rosewater, they need more than just knowledge of human
nature—human nature is what caused the war, after all. They do not want to know
about the world; they want a different world.

Furthermore, it is clear that Vonnegut wrestled
with writing the book he wanted to write in a conventional manner, since the
experiences he had, and his few memories of them were far from conventional. On
Tralfamadore, none of these conventions exist. In fact, as Klinkowitz observes,
Tralfamadorian novels “do not look like novels at all”.3
Indeed, Tralfamadorian novels contain urgent, discrete messages that describe
scenes and scenarios. The author of such a novel carefully chooses the messages
so that, when all seen at once, they form a profound image of life. It seems
that Vonnegut has taken this template as a model for Slaughterhouse-Five. Thus, in the novel, the correlation to
Billy’s time travel and adventures on Tralfamadore is Vonnegut’s own experience
in wishing to write about his Dresden experience, being frustrated in trying to
do so the conventional way and finally breaking those conventions in order to
get the job done. Furthermore, William Rodney Allen suggests that by making the
autobiographical “frame: of the novel part of the novel itself, Vonnegut as
Lundquist puts it “conceptualizes his own life the way he later does Billy’s,
in terms of the Tralfamadorian time theory”.4

1 Vonnegut, Slaughterhouse-Five, 145.

2 Vonnegut, Slaughterhouse-Five, 73.

3 Klinkowitz, The Vonnegut Effect, 83.

4 Allen,
“Slaughterhouse-Five”, 6.