Traditional Tunes of the Child Ballads by Bertrand Bronson
Availability: This title is currently out of print. You can buy it in zShops, or order it used.
Amazon provided the above and then below I saw something showing a price of $675, so I think you will really enjoy reading this at your local library. It is a massive work, so decide first what ballads you want to look up and study. There may be a lower price. In the 70's the paperback sold for about $40 oer volume.