When setting up microphones and other sound equipment, its necessary to perform a Soundcheck. The check can range from the old stand by, "Check 1-2-3", to entire songs for those who got to the show early enough, such as the one by Less than Jake.

The purpose of a soundcheck is to make sure that the volumes are set and mixed properly. Without a soundcheck, you'd always have the case where the guitar is too damned loud. I'm not sure how effective soundchecks are since invariably at every show I attend, after the first song, the band spends four or five minutes yelling at the sound guy to have him adjust this or that level.