If you can handle Victorian stuff, Thomas Hardy used a lot of old songs in his stuff (the two novels in particular that come to mind are _Tess of the d'Urbervilles_ and _Far From the Madding Crowd_). Personally, I'm a bigger fan of _Madding Crowd_. There is a great 1967 movie version of it starring Alan Bates and Julie Christie, which includes "Bushes and Briars", "One Morning in May"/"Bold Grenadier" (some version of that song), "Harvest Home", "Soldier's Joy", and a lovely tune that I've only found as an untitled "Dorset Four-Hand Reel". Not all of the tunes are mentioned in the novel, but there is enough talk of music in it that it's certainly no stretch to put them in the movie.