Which type of music emphasized vocal harmony among multiple singers?

The correct response is motivated by the nature of motets, which are a form of polyphonic vocal music that gained prominence in the late Middle Ages and the Renaissance. Motets are characterized by their intricate vocal harmonies, often involving multiple independent vocal lines sung simultaneously, creating a rich tapestry of sound. This emphasis on vocal harmony is essential to the definition of a motet, as it typically incorporates both sacred and secular texts, allowing for expressive interpretations through harmony.

In contrast, chant primarily refers to monophonic music, which features a single melodic line, meaning that it does not emphasize vocal harmony. Antiphons, while also featuring vocal elements, consist of short sentences sung in a call and response format and do not showcase complex harmonies like motets do. Solos focus on individual performances, which inherently lack the vocal harmony found in ensemble pieces like motets. Overall, the defining element of motets is their intricate and harmonically rich vocal compositions, distinguishing them as the correct choice among the options provided.