In the 17th-century Italian operas and cantatas, the term has essentially the same meaning but is applied to short instrumental conclusions added to an aria or a song. Sometimes the ritornello also occurs at the beginning of the song. Aside from the sinfonias, which serve a different purpose, the ritornelli are the only instrumental pieces in early operas. The ritornello instrumental refrain is a standard feature of German 17th-century strophic songs (arias).
The Ritornello form is a term often used for the typical form of the first and frequently also the last movement of the baroque concerto, particularly the concerto grosso. Such movements consist of an alternation of tutti and solo sections, the tutti sections being based on identical material while the solo sections vary. The tutti sections therefore form the ritornello.