Focus on this artwork and explain the Style.
This lithograph is characterized by smooth, curvilinear forms whose volumes are rendered with the even gradients of tone typical of Rivera's style. Rivera achieved the varied tones within the print by shading and crosshatching with lithographic crayon. Rivera used tonal variations in the black and white Zapata to similar effect as he did color in the painted murals he used as its source material.  In the lithograph, the lightest areas in Zapata's white clothing and the white body of the horse he leads are sharply delineated against the dark background and the mid tones of the clothing of Zapata's followers. This contrast draws the viewer's attention to the figures of the rebel leader and the horse and establishes their preeminence within the composition. In his mural, Agrarian Leader Zapata, one of the sources for the lithograph, Rivera accentuated the two figures by leaving the fresco's brilliant white plaster undercoat exposed. Though the lithograph is aesthetically inspired by the mural, the close cropping of the scene decontextualizes the figures in the lithograph. The original mural provides a gruesome focal point for Zapata and his followers, however the lithograph, created for an American audience, indicates Zapata's gaze to fall on the floral, tropical setting. This alteration removes the political associations inherent to the mural.Rivera’s print shows parallels with Paolo Uccello’s early fifteenth-century painting The Battle of San Romano (c. 1438). Both works depict a white horse similar in size to the human figures pictured, figures bristling with armaments receding into the background, and weapons underfoot in the foreground. Rivera did in fact make numerous sketches of Uccello's horses during a trip to Italy in 1920–1921.In both its representational quality and its overtly political message, Zapata is typical of Social Realism, an international art movement that aimed to create art that would empower the working class.
Paolo Uccello Social Realism lithograph The Battle of San Romano