[Pitchwife]

In addition to the marketing argument Morth offered, which I agree was probably the main reason, the transition in tone mirrors the journey (not merely geographic) of the Hobbits themselves from the cosy and familiar sphere of the Shire into the larger world where they must face higher, stranger and darker forces.


Today, ironically, the effect of the tone of the first chapters on readers who are drawn to LotR as an ur-text of the fantasy genre and may not even have read The Hobbit before may be the reverse of what Stanley Unwin intended. I remember how, coming from sword & sorcery à la Michael Moorcock, I found the Hobbits and their silly banter rather annoying at first. I think it was the first encounter with Elves that got me.