In his new book, Finishing the Hat, Stephen Sondheim writes about the experience of previews for a new musical in New York -- Merrily We Roll Along, in 1981. Sondheim describes the month as being "spent under the gimlet eyes of theatrical vultures (show buffs, rival producers, gossip columnists and the like)."

That, in a nutshell, is the standard version of what goes on during previews: in the contemporary iteration, everyone is huddling incessantly over their smart phones checking out the latest Internet chatter about the verdict on last night's performance.

While the many talented individuals connected with Women on the Verge of a Nervous Breakdown fervently want the show to please the audience (even those pesky chat-room regulars), the idea that preview-period rehearsals are a display of incessant fretful energy is wide of the mark. Rehearsals are much more mundane: people are busy with the tasks at hand.

If you had attended an afternoon rehearsal this week, for example, you would have seen director Bart Sher on the stage of the Belasco, working with an actor on a scene early in the play, trying to establish the optimal tone for a dramatic moment.

At the same time, downstairs, you might have glimpsed Brian Stokes Mitchell and Justin Guarini re-working the movement for one of their numbers. Their laughter as they rehearsed carried up the stairs into the house.

As you walked through the immediate off-stage space, you would have heard a couple of crew members discussing how to make a piece of scenery in the second act slide on sooner.

And if you slid into a seat in the last row of the orchestra, as I did, you might have had a conversation with one of the show's lead actors as she took a short break from working on her lines. The actor-in-question was de'Adre Aziza, who plays the attorney Paulina and who worked previously at the Belasco in Passing Strange, for which she received a Tony nomination.

Aziza told me Women on the Verge of a Nervous Breakdown was turning out to be an interesting experience because "everybody in the cast is a perfectionist," which, she added, creates a strong impetus to make sure the final product is excellent. Like everyone else in the cast to whom I've popped the question, "How's it going?", Aziza said previews have been both challenging and enjoyable.

Since the production doesn't open until November 4, I can't say yet whether cast members would go quite so far as Mr. Sondheim, who in his new book also says of Merrily previews that "that month of fervent hysterical activity was the most fun I've ever had on a single show." But based on the rehearsals I've seen this week, if the Women on the Verge of a Nervous Breakdown actors aren't having fun they're giving Oscar-level performances pretending that they are!

Brendan Lemon is the American theater critic for the Financial Times and the editor of