Which skill is considered essential for an actor to succeed?

Effective communication and emotional expressiveness are fundamental skills for an actor's success. Acting is primarily about conveying emotions, thoughts, and narratives to an audience, which necessitates being able to express oneself clearly and effectively. Actors must not only understand their characters and the story but also be able to connect with the audience on an emotional level. This connection fostered through expressive communication helps to engage the audience and draw them into the performance, making it a key component of successful acting.

The other skills mentioned, such as technical stage management, musical composition, and costume design, are important in the context of theater as a whole, but they do not directly pertain to the core responsibilities of an actor. While it is beneficial for an actor to have some understanding of these areas, they are not essential for an actor's performance or success on stage. The actor's primary focus should remain on their ability to communicate and express the emotions required by their roles.