A Baroque violin is a violin set up in the manner of the baroque period of music. The term includes original instruments which have survived unmodified since the Baroque period, as well as later instruments adjusted to the baroque setup, and modern replicas. Baroque violins have become relatively common in recent decades thanks to historically informed performance, with violinists returning to older models of instrument to achieve an authentic sound.
The differences between a Baroque violin and a modern instrument include the size and nature of the neck, fingerboard, bridge, bass bar, and tailpiece. Baroque violins are almost always fitted with gut strings, as opposed to the more common metal and synthetic strings on a modern instrument, and played with a bow made on the baroque model rather than the modern Tourte bow. Baroque violins are not fitted with a chin rest and are played without a shoulder rest.
The development of the violin started in the 16th century. "Renaissance violins" of this period are of a wide variety of sizes, from small pochettes through descant, treble and tenor instruments, as a consort. Around 1610, Giovannia Paolo Cima wrote the first sonatas for violin, marking the start of its use as a solo instrument. The size and broad design of the violin became fairly consistent towards the start of the Baroque period, at about 1660. In subsequent centuries, there were a number of gradual changes to the violin and bow. The main effect of these changes was to increase the overall sound and volume of the instrument, to improve the instrument's performance in higher registers, and to enable longer legato phrases. Today's Baroque violins are set up as far as possible in the manner of violins used from 1650 to 1750.
There was no single standard model of violin in the Baroque period. Then, as now, instruments were made by individual craftsmen, to different fashions. The instruments used to play the work of Claudio Monteverdi at the very beginning of the Baroque period differed somewhat from those of late Baroque composers. As a result, a modern player who plays repertoire from throughout the Baroque period but can afford only one instrument necessarily has to make a compromise with an instrument that has recognisably Baroque characteristics, but matches the instruments of any one part of the Baroque imperfectly.