As a new boy to the forum, I was interested to see the previous writers comments on this subject and thought I would add my view.
I am sure that most of us that use this great site copy songs to their songbook to correct and transpose to their chosen key. Surely it would be far less contoversial if the index could also direct a user to the song in already published songbooks. This way a user could see several versions and choose what he/she finds best instead of having a situation where a song could be changed daily if two or more people had differing opinions on what is right.