Please not. Melissa Reese's backing vocals have become quite essential for GN'R's live performances recently. And we're all aware of Chris Pitman's backing vocals, especially on "Jungle", lol.
Yet, they unfortunately tend to put most of Melissa's vocals way too low in the mix most of the time. But you could still clearly hear that those vocals (and obviously her layers) were missing when she had to step out for that couple of gigs.
Chris probably had something to do with the original arrangement and, to my understanding, he's still pretty close with Brain, so they probably just found good terms and left his old takes on it, instead of having Melissa to spend time to recreate them for the studio version.
Frank did fully play on "Hard Skool" though, since they seemed to have rearranged the track. But yes, all the other tracks came out of Brain's drum tracks.
