Hobsbawm/Rude is one book I certainly have got, and read! In fact I'd say it's indispensable for anyone who wants to understand southern English folk song.

Also worth checking out is WH Hudson's A Shepherd's Life: Impressions of the South Wiltshire Downs. It's thirty odd years since I read it, and it's bound to be less authoritative than the Hobsbawm/Rude. But I still remember the extraordinarily rivetting nature of the narrative. In fact, I remember reading it with a record playing in the background. I was so mesmerised by Hudson's prose that, when the record stopped playing and broke the spell, it took me a second or two to work out where I was.