Maggie Delaney-Potthoff’s unique approach to teaching singing is apparent during a visit to one of her voice classes, this one as unusual as her instruction: Singing for Screamers. The class, offered through UW-Madison Continuing Studies, is an addition to Delaney-Potthoff?s established offerings of beginning and advanced voice classes. It is designed for rock ?n? roll performers and ?anyone who just really wants to belt, to get their power out,? she said.