The trouble with 'raw' lists is that even in songbooks titles are extreemely variable, but first lines are much less so. With folksongs even first lines are quite variable, so for these even titles and first lines are often not good identifiers of songs. And of course spelling is often a problem when hunting by key words, because so many words have many different spellings. A good index needs cross reference numbers, and that is really a lot of work.