Opera refers to a dramatic art form, originating in Europe, in which the emotional content is conveyed to the audience as much through music both vocal and instrumental; as it is through the lyrics. By contrast, in musical theatre an actor's dramatic performance is primary, and the music plays a lesser role. The drama in opera is presented using the primary elements of theatre such as scenery, costumes and acting. However, the words of the opera, or libretto are sung rather than spoken. The singers are accompanied by a musical ensemble ranging from a small instrumental ensemble to a full symphonic orchestra.