Look 2 (
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Look 3 (
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Look 4 (
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In “A Life in the Theatre,” David Mamet’s comic valentine to the stage, Patrick Stewart and T.R. Knight play actors yoked together in a barrage of bad plays, malfunctioning props and bizarre headgear.

All told, they undergo 26 costume changes in 90 minutes — and fans of Stewart’s chrome-domed “Star Trek” Capt. Jean-Luc Picard may be amused to see just what they’ll plunk on his head next.

We asked Stewart to walk us through a few of his get-ups as Robert, the overbearing ham of the play, and asked what — from his own long life in the theater — came to mind.

Look 1 (far left): “I never wore anything like this before. It looks like who I’m supposed to be, some ancient old dying character in a Chekhov play. I usually wear that hat further forward so less of my forehead’s exposed. I suppose this has a look of Scrooge about it, but my Scrooge didn’t look like that.”

Look 2 (middle left): “I never wore a First World War costume in my life. In the Scottish play [‘Macbeth’], two years ago, we were dressed to resemble an Eastern-bloc military during the Cold War — it had a rather Russian look to it. I wear trousers now in this scene. There was no justification for having bare legs and boxer shorts, and it made other costume changes more complicated.”

Look 3 (right): “In this scene, a flag, my wig and a fan [cause a wardrobe malfunction].” This costume mishap reminds him of “one ghastly winter’s night when the train to Stratford was held up; this was before cellphones. The train finally pulled in at around 10 minutes to 7 and the curtain went up at 7:30. I raced along the platform to where the taxis were, and there were 50 to 100 people ahead of me. Shouting, ‘Theatrical emergency, theatrical emergency!’ I pushed someone away and grabbed their taxi. I got to the theater about five minutes after the curtain should have gone up. Standing outside my dressing room was the brilliant Corin Redgrave, my understudy, wearing my costume — which luckily was only a toga, since we were doing ‘Julius Caesar.’ I remember ripping it off him and saying ‘Get out of those things!’ But he understood.”

Look 4 (bottom left): “This is my shipwrecked-sailor look. What I’ve not done yet is put on the long gray beard and mustache . . . When we started previewing this play, one of my lines was getting a laugh and I had no idea why. It’s when I’m sticking on this beard and mustache, turn to T.R.’s character and say, ‘There must be law, there must be reason — there must be TRADITION!’ And the audience laughed. I asked the director why and he said, ‘It’s because you look like Tevye, that’s why.’ Oh! So the next night, I said, ‘Tradition!’ furrowed my brow and quietly hummed [the ‘Fiddler on the Roof’ song]. The director was waiting for me when I got offstage. ‘Never do that again!’ he said. It was cheap and amused me, but it didn’t amuse our director.”