Mournful though it be, the revival of Parade is cause for celebration. Alfred Uhry and Jason Robert Brown’s musical tragedy, about a grave miscarriage of justice more than a century ago, lasted only a few months in its original 1998 incarnation. But director Michael Arden’s heart-piercing new production, introduced at City Center’s Encores! series last year and now playing a limited run at Broadway’s Jacobs Theatre, makes a masterful case for giving the show a new hearing—and what you hear at this Parade, as sung by a splendid cast led by Ben Platt and Micaela Diamond, will echo for a long time to come.