Denise Clark's passion for helping troubled kids led her to open Main Street Café five years ago as a sanctuary from temptations more dangerous than rock and roll. In other words, it's a drug- and alcohol-free place to rock out. "It's about building healthy relationships and helping kids who are messed up," Clark says. The nonprofit club existed in a couple of other locations before inhabiting the loft at 3111 Wyandotte. With its high ceilings, walls of brick and graffiti, and motherly overseer, the converted warehouse is the kind of place that parents can feel OK about taking their teens. And it's somewhere teens actually want to go. Young folks flock to Main Street about twice a week for concerts by local and national acts. They climb the stairs and go left into a coffee shop and thrift store or right into the big room, where the music happens. Depending on the night, they might hear pleasant, piano-based melodies or guttural metalcore screams. Clark, whom the underage customers know as Mama D, watches it all from the side of the stage, secure in the knowledge that whatever the racket sounds like, it's good for the kids.