Ritornello

A ritornello (or refrain) is the part of a rondo, which is repeatedly recurs in the course of a piece of music and, interrupted by contrasting interludes, called couplets.

When the solo concerts of the Baroque one often speaks of the ritornello; so refers to the division in tutti and solo sections, which became popular mostly by Antonio Vivaldi. The concert will be opened according to this principle with an orchestral ritornello, followed a musical often contrasting episode of the solo instrument. Then the orchestra the ritornello in several transformations, often shortened resume, alternating with virtuosic solo passages. Only the Schlussritornell is repeated in full in general. In marked contrast to the ritornellos often only in basso accompanied solo parts are (episodes), whose harmonic function is to modulate to the key of the next ritornello.