A rehearsal is an activity in the performing arts that occurs as preparation for a performance in music, theatre, dance and related arts, such as opera, musical theatre and film production. It is undertaken as a form of practising, to ensure that all details of the subsequent performance are adequately prepared and coordinated. The term "rehearsal" typically refers to ensemble activities undertaken by a group of people. For example, when a musician is preparing a piano concerto alone in her music studio, this is called "practicing", but when she begins to practice the concerto with an orchestra, this activity is called a "rehearsal".