I would cite Bob Copper's "A Song For Every Season" as an example of history/biography informing us about music. Running through his account of his family's life in the Sussex village of Rottingdean, and stories of the village and its doings, are the songs which were communally sung throughout the year - and the reasons for singing them at particular points in the year. Very informative about the music - with all of them written down in the book.

It's a wonderful book, and I read it regularly to remind myself of what an oral tradition is, and how it flourished (and still flourishes) in Bob's family even though he's no longer with us.

There are also interesting accounts of musical scenes in Thomas Hardy's writings - and his tune book is, I believe, housed in the Dorchester Museum. The tune book might be seen as a snapshot of what was in vogue in his younger lifetime.