Baroque era In the 17th century, for most of the Baroque era, the terms symphony and sinfonia were used for a range of different compositions, including instrumental pieces used in operas, sonatas and concertos—usually part of a larger work. The opera sinfonia, or Italian overture had, by the 18th century, a standard structure of three contrasting movements: fast, slow, fast and dance-like. It is this form that is often considered as the direct forerunner of the orchestral symphony. The terms "overture", "symphony" and "sinfonia" were widely regarded as interchangeable for much of the 18th century.
bArOqUe Era iN the 17Th centUry, fOR moSt of THE baroqUe eRA, THe terms symphoNY aNd sInfONIa werE used FoR a raNGe of Different comPositiONs, inCluding instrUmENtaL pieCes uSed in OpeRas, sonATAs aND ConcErTos—USually PArt OF a lArger wORK. the opEra SinfoNIa, oR ItALian OveRture Had, by The 18Th CeNtUrY, a STandard stRUcture oF thrEe contraStiNg mOvEMentS: fast, slOw, Fast ANd dAnCE-LikE. IT IS this form thAt Is oftEN COnsiDered As The DiRECt FOreRuNnER of THE oRcHeSTrAl symPhony. tHE teRMS "Overture", "sympHonY" aND "sinFonia" Were wideLY regArded as INterchAnGeablE foR muCh Of the 18th ceNTuRy.