hey guys
can some one give an insight into phase reversal in the mix how often it can be used and where it is most relevant?
Page 65 of the dance music manual 
Just remember, things out of phase = bad. If you have 2 similar frequencies, like a kick and sub bass and they are 180 degrees out of phase, they will cancel each other out. This is the worst case scenario but phase problems can be all over the mix killing sonic quality. You can use phase detecting plugins to help you get a handle on this.
phase detecting plugins you say? That sounds interesting, got any recommendations?