I just did another 20 minutes of tweaking, I've run with the dark club feel.
Apart from vocals, chorus synths, bass & drums I've tried to blend the other audio, more or less, into one sound in which different parts pop their head up for attention. I felt this added to the energy of the song.
I guess I spent around 6 hours on this in total.
Phew, it's over!
Click here to listen to the mp3

