Curator Leah Dickerman discusses the murals and career of Diego Rivera. “Diego Rivera: Murals for the Museum of Modern Art” is on view at MoMA through May 14. The exhibition features murals, which are up to six feet by eight feet in size and weigh as much as 1,000 pounds, made of frescoed plaster, concrete, and steel. There are also three working drawings, a “portable mural” made in 1930, and smaller prints, watercolors, and drawings.