Metal band Dream Theater has spent almost 30 years honing its aggressive, technically superb hard rock. After developing an underground fan base, the group saw mainstream success when its 1992 single “Pull Me Under” became an MTV hit. Since then, the band has sold out thousands of shows and developed a reputation for high-energy, unpredictable concert performances. The group is now touring in support of its latest release, “A Dramatic Turn of Events.” Dream Theater performs at the National on Thursday, July 12, at 8 p.m. $35-$38. 612-1900.