introduction

In music, a section preceding the main body of a work. Many symphonies of the 18th century featured a slow introduction (including works by Haydn, Mozart, and Beethoven), and this practice was sometimes transferred to quartets and keyboard works, as in Beethoven's Sonata Pathétique (1799). The introduction may be related motivically or thematically to the rest of the work, as in the Pathétique, or it may be more independent, as in Edward Elgar's Introduction and Allegro (1905) for strings.