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Alex Kalman does things that Max Hollein of the Metropolitan Museum of Art and Glenn D. Lowry of the Museum of Modern Art do not, like sweeping the street in front of his museum.

Mr. Hollein and Mr. Lowry run two of the largest art collections in New York City. Mr. Kalman, 33, runs one of the smallest — all 36 square feet of it. That is one eighteen-thousandth the size of the Met. The only thing that is oversized about it is the name: Mmuseumm, with a couple of extra “m’s.”

Other museums have big curatorial staffs. Mr. Kalman is the curatorial staff at Mmuseumm, on Cortlandt Alley in TriBeCa .

So there he was with a broom, outside, and when he went inside, it was not like going up the steps from Fifth Avenue and into the Met’s Great Hall. Mmuseumm has no steps. It occupies what used to be a freight elevator that opened directly onto the street.