Should poetry be a non-count noun? When it is a thing?
There’s a poem. There, say.
But it rarely being finished, when it is radically, substantially edited, when is it a second thing? When it becomes a story it ceases being a poem, probably.
A book is a thing. It may be made of poems. How to count?
Is a crown of sonnets one? Is a series one? Is a book-length poem one?
What is a unit?
Let’s pretend we know what a poem is.
When is it a chapbook? What is a chapbook? Does it stand alone? Is a chapter of a series that becomes a book? Is it a unit by itself that won’t grow to book size?
A poem or a chapbook or a book may be a size of a thought.
A word may be the size of a thought. Or an essay. Or for really single-minded people, a life may be dominated by the pursuit of expression of one thought.
What’s a chapbook vs. a book?
A chapbook may test the water for an expansion to a book. Small press run, local audience, or speciality thoughts to go to a group geographically widespread but scant.
A chapbook may be the final thing.
A chapbook may be a business card to announce your arrival in community.
A chapbook may be as elaborate as a book, just incidentally have fewer pages than the UN definition of a book.
A chapbook may feel like a cohesive whole or be a finger held in the air holding the floor (which is presumably above one’s head spinning like a plate). It may string together the best so far that eventually will spread apart and be filled in with other projects.
A chapbook may be part one of a few, a serialized book.
What is a poetry book? A lineated essay to explore an idea, a collating of a few unrelated chapbooks, a first in a series of books, bound to a size that is a commercially viable number of pages, a chapter on one aspect, a diary well-written for public reading, an exercise of mind and language and experience, a bit of the body flaked off to be of use to others, like an organ donation with no pre-arranged patients.