I get using use the Artistname and Songname for searching. But, what happens when one or both are unknown? There is a site that searches for songs by lyrics (good for text searching), and one by uploading a sample file (good for instrumentals and unknown versions). But most times, I get "no res...

Sounds like this only tags files from publishers. What about songs recorded from radio? (Audio Tag . info) lets you upload a file for analysis, then lists possible results for you to manually tag the file with. How does this program actually identify a file? What does it look for? What does the file...