I just did release edit http://musicbrainz.org/edit/14471721 to break up artists such as "Johnny Cash & Jerry Lee Lewis & Carl Perkins" into the three distinct artists on a VA release. It was clear how to do this, but it was a bit of a pain having to re-search and enter for three artists for each of the four tracks they all appeared on. It would be nice if I could just copy and paste the correct artist credit for the other three tracks