By Denny Dyroff, Entertainment Editor, The Times Allegaeon Fans of metal music will be in a state of ecstasy on March 20 – and not because it’s the first day of spring. The reason for their delight will be mega-show at the Voltage Lounge (421 North Seventh Street, Philadelphia, 215- 964-9602, www.voltagelounge.com) featuring a sextet of top-flight metal acts. The “Dank Memes Tour 2018”...