Backstage is
VERY NEGATIVE:
"In director Scott Elliott's revival of Eugene O'Neill's comedy Mourning Becomes Electra -- wait a minute. This isn't a comedy. It's a tragedy, a trilogy, 13 acts in all, about a family violently disintegrating after the Civil War, a conscious, monumental remaking of Aeschylus' Oresteia with American values, faces, and voices. Why did the audience laugh?
First, forgetting the Aeschylus-O'Neill parallels, audiences know soap operas when they see them, and Mourning Becomes Electra is that if nothing else..."
http://www.backstage.com/bso/news_reviews/nyc/review_display.jsp?vnu_content_id=1003943177
"Y'know, I think Bertolt Brecht was rolling in his grave."
-Nellie McKay on the 2006 Broadway production of The Threepenny Opera, in which she played Polly Peachum