Given the task definition and input, reply with output. This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Passage: Works of classical repertoire often exhibit complexity in their use of orchestration, counterpoint, harmony, musical development, rhythm, phrasing, texture, and form. Whereas most popular styles are usually written in song forms, classical music is noted for its development of highly sophisticated musical forms, like the concerto, symphony, sonata, and opera. Question: Works of classical repertoire exhibit what in their use of orchestration and harmony, and form?

complexity