William Prinzing Briggs, music director of the Central Kentucky Youth Orchestras, discusses the Classical period in music, including the qualities of balance and structure; the importance of melody; theme and variations; the string quartet; the four movements of a classical symphony; and the solo concerto form. A string quartet from the youth orchestras performs excerpts from Haydn’s Divertimento in C for String Quartet, Mozart’s String Quartet in C, and Haydn’s Theme and Variations on “God Save Francis the Emperor.”