One of the many wild cards at any live show is the person behind the board, and those techs have a bigger impact on your actual performance than just about anyone else outside of your band. Club owners can stiff you on pay. Fans can fail to show up or turn out in throngs. But the sound tech controls what you actually sound like, whether you can transmit your ideas and emotions to a live crowd. This calls for quickly making friends with the pros running your sound and communicating your needs and wants in a way that's clear and professional.