I guess I've got Hamlet on the brain, and it's pertinent because I've come up with two separate, and wholly different query letters to send out to agents. Only, I'm unsure of which one to send off.
With a book I was able to draft the second one, which I believe far better than the first, only it doesn't have the sound of a typical query letter. This is both good and bad as I'm sure agents are tired of the same types of query letters they get, but there is the matter of formality that has been established for certain purposes. I believe I follow the formalities in form and in function, but not in voice. I've taken the suggestion of the book and put in the voice of my work into the query letter, mainly the clipped, hard-boiled speech so common in the works of Hammett and Chandler. I believe this voice vastly improves the letter, making it immediate engaging and pulling the reader into the mode of the story through the letter itself, making for a good lead in to the chapters in the story.