Most plays get dated, but social-protest plays date more rapidly than others. They stand still while times change. Addressed to a flaming grievance, they lose their fire as the grievance is redressed. In Depression days, when unions were weak and embattled, the fierce rallying cry at the end of Clifford Odets' Waiting for Lefty"STRIKE! STRIKE! STRIKE!" brought audiences to their feet with huzzahs. Today, playing before audiences sated with strikes, the line might well garner some Bronx cheers.
Similarly, the musical Purlie, fashioned from the straight play Purlie Victorious, which opened on Broadway...