Question

Question was provided via image upload.

Explanation:

Identify the musical form context

Using the Ritornello Form and Rondo Form knowledge points, we analyze the structural behavior of recurring themes. Both ritornello form (common in the Baroque era) and rondo form (common in the Classical era) are defined by a recurring main theme or "opening idea" that returns periodically.

Analyze the behavior of the returning theme

Using the Ritornello Form and Rondo Form knowledge points, we determine the key relationships of these returns. In standard rondo form (typically \(A-B-A-C-A\)), the main theme (\(A\)) almost always returns in the tonic (home) key to provide tonal stability and resolution. Similarly, in ritornello form, while intermediate statements of the ritornello can occur in related keys, the final statement returns fully to the tonic key. Therefore, the defining characteristic of a returning opening idea in these forms is that the opening idea returns in the tonic key.

Answer:

• A new idea occurs in the tonic key.
• The opening idea returns in a new key.
• A new idea occurs in a different key.
• The opening idea returns in the tonic key. (Correct answer)