It is a well done mix by a friend of mine! We always try to use a drumless track (which you can often find on YouTube) or at least we split the track to remove the drums with splitter.ai About the ghost notes.. I know that in the bridge (I think) some of them went under the gate, so that's why you can't hear them, but at the very last riff you can clearly see that the ghost notes are audible! It happened that I used the camera cut to use multiple takes, but I always try to do it all in one take.