The feature that makes this excerpt a blank verse is that , while it does not present rhyme, it does present iambic pentameter.
Iambic pentamenter consists of lines of five <em>feet</em>, with each <em>foot </em>being two syllables long, one unstressed followed by one stressed syllable. The result is that each verse sounds like it has a heart beat rhythm.
My heart is happily singing,
Whos cuddling on the couch,
My heart is full
Like fruit on a tree
My heart is loving
who is nonstop
My heart is happier than the rest,
Because I have my love
This was an event in Vonnegut's own life, and the novel is
considered semi-autobiographical. from his time as an American soldier and
chaplain's assistant, to post war and early years. It is generally recognized
as Vonnegut's most influential and popular work.