Alan Cumming stars in Macbeth at the Ethel Barrymore Theatre; photo: Jeremy Daniel

Alan Cumming is so fascinating as Macbeth that it is a wonder no one has yet cast him in a production of Macbeth. The current Broadway production is not quite Macbeth and not quite not Macbeth. It is not quite a one-man show and not quite not a one-man show, not quite Shakespeare and not quite not Shakespeare.

The Macbeth being presented at the Ethel Barrymore Theatre is a slightly revised revival of Mr. Cumming’s one-man Macbeth presented at Lincoln Center over the summer. I am happy it has been brought to Broadway: The less interesting political theater of the summer—the presidential nominating conventions and campaign—kept me away, and left me with a significant hole in my growing Macbeth collection. (To miss a play about the coarse and bloody-minded pursuit of power while observing a presidential campaign is an odd sensation: Mr. Cumming was playing Macbeth, and I was watching the nonfiction version of sound and fury signifying zilch.) At any rate, I now can fill that particular Macbeth-shaped hole with a roughly Macbeth-shaped object.

This Macbeth is a mental patient. He is obsessing over the events that have scarred his psyche, jabbering either at no one in particular or at himself or with the interlocutors in his mind. It is not a blazingly original idea: An opera recently presented at the University of California at San