What is a "compound music form" made up of?

A compound music form is characterized by its structure, which consists of smaller, simpler forms such as binary and ternary forms. This concept highlights how larger musical compositions often utilize these basic forms as building blocks. In compound forms, these simpler structures are combined in various ways to create a more complex overall structure, allowing for greater development and contrast within the music.

For example, a piece might contain several sections that follow a binary format (A-B) or a ternary format (A-B-A), and these sections could be linked together in a manner that contributes to the work's overall narrative or thematic development. This layering of formats allows composers to expand their musical ideas while maintaining clarity through recognizable forms.

The other choices do not accurately describe what a compound form comprises. Blending different genres is a stylistic approach rather than a structural one. Unrelated ideas combined would suggest a lack of coherence, which contradicts the organized nature of compound forms. Lastly, mixing solo and ensemble pieces pertains more to performance context than to the structural aspect of music forms.