Back when Lily Tomlin first toured in The Search for Signs of Intelligent Life in the Universe, the one-person ensemble drama was a novelty. These days, the genre is such a staple that merely being chameleonic is sometimes seen as insufficient; performers feel they need tricks to set themselves apart. Anna Deavere Smith goes barefoot. John Leguizamo emphasizes ethnicity. Charlie Ross does movie trilogies. Jefferson Mays does drag. (So does Lypsinka of course, but that’s another genre.)

Nilaja Sun’s No Child doesn’t rely on gimmickry, though I’m guessing it will sound conventional enough in précis that you’d forgive her if it did. The evening is about a drama teacher who tries to inspire alienated kids in schools where the metal detectors work better than the toilets. Sound familiar? It’s territory Michelle Pfeiffer, Edward James Olmos, and Sidney Poitier have all traversed before Sun, albeit onscreen and surrounded by other actors.

So why return to it solo? Well, partly because Sun’s experience is personal. She created this hour-long evening while working as a visiting “teaching artist” in New York City’s toughest schools, so it’s partly because she has something to say about the No Child Left Behind testing mandates that, even in the world’s most culture-rich metropolis, limit school arts spending to the hiring of visiting teaching artists.

And partly because she really is a gifted chameleon. Watch as she uses a simple shift in posture to transform a timid Asian teacher into an attitude-reeking gang member without the latter ever speaking a word. And note the seeming ease with which she keeps a dozen students and teachers present and accounted for during a performance of a play-within-a-play, while also making you painfully aware of the one kid who’s not there.

Does she go for laughs more frequently than she might? Sure. And yes, the evening ends a tad awkwardly, with a movie-ensemble trope that’s not quite right for the stage. But it also ends long before you want it to, and given the territory being covered, that’s saying a lot.