Which opera style is characterized by serious subjects and alternating recitatives and da capo arias?

The correct answer is Opera Seria, which is a style of opera that emerged in the late 17th century and was prominent throughout the 18th century. This genre is known for its serious themes, often grounded in mythology, history, or romanticized narratives involving noble and heroic figures. The structure of Opera Seria includes alternating recitatives and da capo arias, where the recitative serves as the narrative dialogue and the da capo aria provides a moment for emotional expression, typically featuring a return to the initial theme of the piece after a contrasting middle section.

This format allows for a balance between storytelling and lyrical flourish, which is essential for conveying the dramatic weight of the serious subjects explored in these operas. The heavy use of da capo arias showcases the virtuosity of the singers, which was highly valued during this period.

In contrast, other styles like Opera Buffa deal with comedic subjects and use simpler structures, often foregoing the strict adherence to alternating recitatives and da capo arias. Musical Theater combines popular styles with a broad range of thematic elements, while Chamber Opera indicates smaller-scale operas that may explore varied subjects but do not have the defining characteristics of seriousness and structural formality found in Opera Seria.