Never apologize, never explain: the familiar aphorism is usually invoked after the fact, when the apologizing or explaining has been done, to deleterious effect. It sprang to mind again as I read the letter that Tim Sanford, the artistic director of Playwrights Horizons, sent to some subscribers of that Off Broadway theater, offering a long and eloquent explanation (with a spoonful or two of apology) of the theater’s decision to mount “The Flick,” the new play by Annie Baker.

A gentle study of the relationships among three workers at a dingy movie theater in Massachusetts, the play opened to largely rapturous reviews this month and subsequently won the prestigious Susan Smith Blackburn Prize. But it has caused consternation among some of the theater’s patrons. Many have left at intermission after venting their irritation and in some cases threatening to cancel their subscriptions. For the first time in his 15-year stewardship of the theater Mr. Sanford felt the need to calm ruffled feathers or at least make a spirited case for the theater’s right to ruffle them now and then.

The e-mail message, sent only to the 3,000 subscribers who had already seen the play, runs to almost a thousand words: virtually a novella in this era of “c-u-l8r” quick-bite communication. I rather savored its length, given that the chief problem some theatergoers have with the play is its length: three hours. If Mr. Sanford’s patrons don’t have the patience for a play that, by the standards of theater from the Elizabethan era onward, hardly qualifies as epic length, would they really want to read a long defense of it?

In an interview with my colleague Patrick Healy, Mr. Sanford said that the letter was “not an apology,” and its length speaks to the difficulty of what Mr. Sanford perceived to be the task at hand: “I wanted to explain my thinking to our subscribers and also explain our mission as a writer’s theater, in hopes of making this a teachable moment,” he said.