The elements or basic ingredients of music are defined. Some of the musical excerpts in Episode 3 receive brief encores to prod the viewer's memory. Very brief references to the 1st movement of Mozart's Piano Sonata, K. 545; Bach's Little Prelude in D, BWV 936; 3rd movement of Rachmaninoff's Symphony No. 2; 1st movement of Mendelssohn's Symphony No. 4, "Italian" and Morton Subotnick's Silver Apples of the Moon - as well as a bit of humor - are all used to refine these definitions.