The main term we’re going to use to describe Melville’s tone in Moby-Dick is versatile. It’s almost as though, to prove his greatness as a novelist, he’s writing his way through a variety of tones the way a singer might practice all the notes of a scale. Just to show you how densely compacted these different degrees of tone are, we’ll point them all out using examples from the first chapter alone.
The "default" tone in Moby-Dick is thoughtful, with a dash of humor and affection – the tone Ishmael (or Melville) often adopts when he’s considering scenes of whaling and sailing that are dear to his hear. We find this tone in the very first paragraph of the novel:
Whenever I find myself growing grim about the mouth; whenever it is a damp, drizzly November in my soul; whenever I find myself involuntarily pausing before coffin warehouses, and bringing up the rear of every funeral I meet; and especially whenever my hypos get such an upper hand of me, that it requires a strong moral principle to prevent me from deliberately stepping into the street, and methodically knocking people’s hats off – then, I account it high time to get to sea as soon as I can. (1.1)
But this flippant, affectionate, self-mocking humor that Melville uses when discussing the details of a seafaring life can turn into bitter sarcasm at a moment’s notice:
The urbane activity with which a man receives money is really marvellous, considering that we so earnestly believe money to be the root of all earthly ills, and that on no account can a monied man enter heaven. Ah! how cheerfully we consign ourselves to perdition! (1.10)
Both the gentler humor and the scathing sarcasm can disappear when Melville wants to play up the literary qualities and symbolic register of Moby-Dick:
By reason of these things, then, the whaling voyage was welcome; the great flood-gates of the wonder-world swung open, and in the wild conceits that swayed me to my purpose, two and two there floated into my inmost soul, endless processions of the whale, and, midmost of them all, one grand hooded phantom, like a snow hill in the air. (1.14)
By demonstrating to the reader how easy it is for him to traverse the great distance between the grand "flood-gates of the wonder-world" and the comical "damp, drizzly November" of Ishmael’s soul, Melville get to show off his superior writing skills.