When did symphonies start?

The origins of the symphony can be traced back to the 17th century, when opera overtures and other orchestral works began to be composed in a multi-movement form. These early symphonies were often called _sinfonias_ and were typically in three movements: a fast first movement, a slow second movement, and a quick third movement. The modern symphony, with its four-movement structure, developed in the 18th century, thanks in part to the influence of composers like Joseph Haydn and Wolfgang Amadeus Mozart. Haydn is often credited with being the father of the symphony, and his symphonies helped to establish the genre as a major form of classical music. Mozart's symphonies further refined the genre and brought it to new heights of popularity. By the early 19th century, the symphony was a well-established and widely-performed musical form, and it continued to be developed by composers throughout the Romantic and Modern periods.