The three characters — a male acrobat, his female partner and a male singer — all perform in what appears to be the same Broadway theater. The story traces the lady acrobat from glamorous stage performer to slum drudge and then (allez-hop!) a last-page return. Gropper’s main influences were fellow satirists like George Grosz, but, with its curves and filigrees, the figure drawing in “Alay-Oop” also has traces of Lautrec and Degas. His line is loose and fluid; his humor is sly; his designs are strikingly economical.