Toms sound advice
The sound guy (or girl) is the most important component of your show that most bands don’t really think about.
He or she can break your set (few sound guys can actually make your set ). But the band can help by keeping all vocal mics at about the same level for blended harmonies.
For any one who plays in a band or makes a recording, - when you want something to be louder in the mix, consider that maybe everything else should be quieter?