Originally Posted by Freebase Dali

Well, in this particular scenario, you're all of it.
The idea behind mastering in an album sense, in our scenario anyway, is getting all the songs to a cohesive tonal balance and volume, and arranging the songs in a fashion that's not random and creates a progression throughout the album.

Instead of just saying "Ok here's 12 songs, I'm going to randomly put numbers on them and make sure all their peaks hit around the same DB level" isn't going to give you good results.
Some songs may need a little bit of compression to even out the dynamics a bit, others may need a little bass removed (like mine), while others may be just right.
The idea is to make the album cohesive and make it flow, possibly fix some glaring frequency errors, and add a little sparkle and sheen.

Obviously, if any major work needs to be done, the person mastering the album would provide the artist with the edited work for approval, or ask the artist to bring something up or down in the mix, but judging from the submissions we had in the members comp, most of everyone's sound was good and maybe just called for some light compression and limiting across the board. And above all, some arrangement.