Sinfonia

Sinfonia is the Italian word for symphony. In English it most commonly refers to a 17th- or 18th-century orchestral piece used as an introduction, interlude, or postlude to an opera, oratorio, cantata, or suite. It has also sometimes been used for other types of music.

Read more about Sinfonia:  Late Renaissance – Early Baroque, Overture or Early Symphony, Symphony With An Alternative Scope