Dear WO'N: This opera had permission of O'Neill's widow, and was performed at Metropolitan,
so it ought not be a sad travesty of original, at least as far as essentials of plot are concerned.
If You navigated the URL I gave, the credentials of the lyricist seemed acceptable. I cited it
hoping it was a reasonable approximation of original, synopsised to make quick read.
So sue me.

Here is review from New York Times:

"There is a rhythmic inventiveness and pulsating drive to the music that seems a bracingly American
aspect of Mr. Levy's Expressionism ... the score teems with surging music ... gripping ... and, as someone
who knows the ways of the theater, he can create characters through music. He has given us an
engrossing musical drama. How Mourning Becomes Electra stacks up against the works of Strauss and
Berg or other giants is to me a boring question. Let history decide. A fascinating new opera held my
interest and stirred the audience."

Anthony Tommasini, The New York Times