It's mentioned in the passage that ………..

An orchestra is a fairly large ensemble of musical instrumentalists. The orchestra, and the history of orchestral music, is considered to have started with the operas of Claude Monteverdi. Its familiar composition, divided into four basic groups of instruments - strings, woodwind, brass and percussion - dates from the second half of the 18th century and is especially connected with the work of Joseph Haydn. The orchestra grew dramatically in size during the 19th century, from an ensemble of 35 players to a company of well over 100. During the same period, the composition of orchestral music and the particular use made of individual instruments or groups of them, increasingly became the hallmark of a composer's individual style.