The Baroque period is from roughly 1600 – 1750, and includes composers like Monteverdi, Vivaldi, Lully, Handel and Bach (to name but a few!). We play at A = 415hz pitch, unlike ‘modern’ orchestras which are tuned a semitone higher. A few SWBO players have original instruments but most of us play on copies of period instruments. The string instruments have gut strings and concave shaped bows, with fewer hairs than modern bows; woodwind instruments are made of wood and have few keys, while brass instruments are ‘natural’, that is they do not have valves to change the pitch.
As a result of all these factors the style of playing has a certain lightness which is in keeping with the dance conventions of the time, and the use of gut strings lends an expressivity which is very different from an orchestra that uses metal strings. Intonation (tuning) is respected thanks to sparing use of vibrato (which can distort the pitch of a note) and keyboard is tuned to a circular temperament (where each semitone is different) (Valotti) rather than the equal temperament of the piano (where each semitone is the same).