Before TV and movies, the most popular form of entertainment for everyday working people was vaudeville -- lively variety shows performed by troupes of actors who sang, danced, told jokes, juggled, tumbled and did just about anything else to please the crowd. MOXIE: A Happenstance Vaudeville pays tribute to this lost art form with a theatrical collage inspired by vaudeville shows of old, infused with the joys and struggles of the vaudevillians' lives. This show at the Round House Theatre in Bethesda is teeming with hijinx, live music, period costumes, physical comedy and nostalgic beauty.