Step-by-step explanation:
String orchestras can be of chamber orchestra size ranging from between 12 (4 first violins, 3 second violins, 2 violas, 2 cellos and 1 bass = 12) and 21 musicians (6 first violins, 5 second violins, 4 violas, 4 cellos and 2 double basses= 21) sometimes performing without a conductor.