Episode Title:Mother Necessity.Episode Description:In a play on the adage "Necessity is the mother of invention," great inventions are set to a series of short, mostly unrelated songs tied together by the titular Mother Necessity (resembling Whistler's Mother), who keeps pictures of the inventions on her wall. In several of the songs, fictionalized accounts describe how struggles of the inventors' mothers inspired major inventions by Samuel Morse, Thomas Edison, Elias Howe and the Wright Brothers.