Perhaps a new page tab or new "Song Editing Forum" section which lists all the recently-edited songs would suffice. Such a listing of all recently-edited songs would allow other users to check the changes and discuss finer points of how to make a song version the best it can be. Such a forum section would also have the advantage of promoting open and rational discussion should disputes arise.
The idea of personal songbook versions appearing in the general index is also worthy of serious consideration. If that is technically possible, then it could be good path. However, for extremely popular songs you could end up with multiple versions of a song that have only minor differences - it would make the process of sifting through all the multiple versions very cumbersome.
Has there been any 'abusive' editing yet?
Has there been any 'dueling editing'?
Any malicious/destructive behavior yet?
Although these unfortumate things may occur every once in a while, the ability of chordie users to readily fix obvious problems with layout and content is a very good thing. Over time, a quality library of accurate songs will emerge.
I would expect that malicious/desctructive editing would be limited primarily to hormone-crazed adolescents and that they would focus their attentions on a rather narrow spectrum of songs available on the site.
Perhaps a simple limit on the number of songs a person can edit per day would provide a guard against psycho-destructive, malicious behavior?
The idea of changes being 'approved' by senior members would seem to be unwieldy and cumbersome - I think a forum section focused on recently-edited songs would serve the same purpose.
"That darn Pythagorean Comma thing keeps messing me up!"