Q: Passage: Orchestras are usually led by a conductor who directs the performance with movements of the hands and arms, often made easier for the musicians to see by use of a conductor's baton. The conductor unifies the orchestra, sets the tempo and shapes the sound of the ensemble. The conductor also prepares the orchestra by leading rehearsals before the public concert, in which the conductor provides instructions to the musicians on their interpretation of the music being performed.

Question: Based on this passage, who is known as the leader of an orchestra?
Let's give stream of consciousness below
The relevant information is: Orchestras are usually led by a conductor who directs the performance with movements of the hands and arms, often made easier for the musicians to see by use of a conductor's baton. So the answer is a conductor.