sentences:  In some regional orchestras, amateur orchestras and youth orchestras, the string sections may be relatively small, due to the challenges of finding enough string players.The music for a string section is not necessarily written in five parts; besides the variants discussed below, in classical orchestras the 'quintet' is often called a 'quartet', with basses and cellos playing together.The role of the double-bass section evolved considerably during the 19th century.