An orchestra can signify the aspects of your personality that have work harmoniously in order for you to function.
Dreaming that you are conducting an orchestra can be a sign that you need to take control of something.
Being a member of an orchestra in a dream is a message that the work you are doing is an important part of a larger task.
Whether you are in tune or out of tune with the orchestra in your dream is an indication of how well you blend in with the people in your life.