Which term refers to the fluency and rhythm that makes a text unique to its author?

The term that refers to the fluency and rhythm that makes a text unique to its author is voice. Voice encompasses the author's distinct personality, perspective, and style of expression in their writing. It is the way an author conveys their thoughts and emotions through language, creating a sense of individuality in their work. This includes the choice of words, sentence structure, and the overall flow of the narrative, all of which contribute to the unique sound and feel of a piece.

While style also relates to the author's choices in writing, it is more about the overall characteristics and techniques used across their work instead of the personal touch and emotional resonance that voice conveys. Tone refers to the author's attitude toward the subject matter and audience, which can change depending on context, but it does not encapsulate the overall rhythm and fluency unique to the author as a whole. Structure refers to the way a text is organized, which is essential to narrative flow but does not define the personal rhythm and fluency of the author's expression. Thus, voice is the most fitting term for the quality that makes the text distinctly reflective of its author.