Charles Dickens, in writing Pip's "voice" in a relatable and compassionate first-person, gives the audience a lot of tonal prompting. That is, the reader is pushed toward feeling what Pip feels, as the first-person narrative only gives one unified perspective on the events of the novel. Like many Victorian realist novels, the tone of the book varies depending on the stage of the narrative. At the beginning, the tone is foreboding, Gothic, and a little frightening, as the narrator recounts the startling events of his childhood and his difficult early circumstances. As the dramatic and often shocking events of the story unfold, the tone alters to match Pip's responses to each occasion.
The tone is also largely dictated by the reactions Pip has to the events he is narrating and his own moral judgements about them. These gradually become more nuanced, aligning with Pip's growing discernment and intelligence as he develops. As a result of Pip's changing personality and accumulation of experience, the attitude the novel takes to events becomes more balanced and reflective.
It isn't all serious, however. The narrator's tone is also often wry and academic, as the older Pip's voice makes highly educated asides and uses wordplay to engage the reader. As the narrator recounts his memories, he is able to see the humor in things that might have seemed tragic at the time, which allows even frightening or uneasy moments to have an entertaining tinge of irony. Although the narrator is very self-conscious throughout this book, and the reader is very aware of his presence because of his regular "interjections," the tone sometimes lightens what would otherwise be deeply tragic scenes with its sense of mature hindsight.