It has finally dawned on me! I guess I'm getting dense in my old age. Probably most figured it out long ago, so this note is really just for dolts like me. I could have saved many hours of searching for ballads on the Bodley Ballads website (in Mudcat's Links) if this had occurred to me several months ago.

The reason for two boxes under Search for keyword in title, first line, or tune (direction) on the Bodley Ballads website is that you can put one keyword in the first box and another in the 2nd box (but only one word per box). This greatly simplifies searching when there are no uncommon words you know in the title, first line, or tune (direction).