“Million Dollar Quartet” is a rockin’ reminder of what went down that fateful day Elvis Presley came back to his former Sun label to tell his buddies about Las Vegas amid other tall tales. Carl Perkins was recording “Blue Suede Shoes” at the time, employing Jerry Lee Lewis as his piano player. Johnny Cash was hangin’ ‘round too. The jams, the convivial camaraderie and the petty jealousies are all on display in this traveling roadshow of the acclaimed Broadway musical that stops at the State Theatre in Easton, Pennsylvania, on Jan. 22. The music, of course, is sublime.