overture, instrumental musical composition written as an introduction to an opera, ballet, oratorio, musical, or play. The earliest Italian opera overtures were simply pieces of orchestral music and were called sinfonie. Jean Baptiste Lully standardized the French overture, using an opening section in pompous chordal style and dotted rhythms followed by a fugal section. This type of overture was much imitated, an example being the overture to Handel's Messiah. In some of the 17th-century Neapolitan operas, to some extent in Jean Philippe Rameau's operas and most notably in Gluck's, the overture began to foreshadow what was to come in the work's tunes. In many 19th-century operas and 20th-century musicals the overture is simply a potpourri of the work's tunes. The concert overture, a composition in one movement that may be in any of a variety of styles, arose in the 19th cent.; the overtures of Brahms, Mendelssohn, and Beethoven are outstanding.