Since its inception in 1996, the WaterTower Theatre has proven that regional theater can be much more than the minor leagues for the performing arts. For instance, It Ain’t Nothing But the Blues this past season was as good as anything on Broadway—heck, it was better. The annual Out of the Loop Festival gives smaller companies and underground plays much-needed exposure. And for everything from an intimate drama to a hand-clapping musical, inventive and impressive set designs make the most of the 32,000 square feet of interior space. If the script calls for rain, you can expect to see raindrops. What you shouldn’t expect at WaterTower are empty seats.