Here's a place where I think Dickens uses a word incorrectly. "Pitch" I have heard used only to indicate the
frequency of vibrations of sound. Orchestras used to tune to a pitch of a pitch pipe, or a tuning fork, etc.

"'Gentlemen,' said the mayor, at as loud a pitch as he could
possibly force his voice to--'gentlemen. Brother electors of the
borough of Eatanswill. We are met here to-day for the purpose
of choosing a representative in the room of our late..."