That "fully searchable" site is a formatted version of Cathy Lynn Preston's concordance, which contains song texts only. The notes are missing, so it's of use mainly to people who already have the books and just want to be able to search the texts quickly. Taken out of context, the material is interesting in the same way as are coins found with a metal-detector and displayed at random with no accompanying information.
In common with "guest", I'll be interested to hear more, though I don't know how relevant the audio tracks will be; most of the names quoted are revival, rather than traditional, singers. Perhaps it will be wonderful; we shall have to see.