The vocal is everything to the success of a song. Make it loud enough to be able to hear the lyrics. The problem is, if the vocal level is too high, all the energy of the track disappears, if it is too low, you can’t understand what is being said.
A mix with a bright vocal and a dull drum sound is really a problem. The all important snare takes up a lot of spectrum and trying to brighten it with eq will make the bright vocal even brighter and quickly become unacceptable.
This is a really important part of getting the balance right in the mix. And, unfortunately, it’s something that a lot of beginner and intermediate mix engineers don’t know about.
My general rule of thumb for pop music is that the vocal is usually about the same (perceived) level as the snare and the sibilance is about the same (perceived) level as the top of the drums – either the hats, snare or overheads.
Also read part one of the interview. Great stuff.