What term describes music consisting of several voices singing in harmony, developed in the 12th century?

The term that describes music consisting of several voices singing in harmony, which developed in the 12th century, is polyphony. This musical style is characterized by multiple independent melodic lines occurring simultaneously, creating a rich tapestry of sound. Polyphony marked a significant evolution in music, as it moved away from the single melodic lines typical of earlier music forms, such as monophony.

During the 12th century, composers began to experiment with writing music that allowed different vocal parts to interact with each other, rather than simply layering voices on a single melody. This development was crucial in the history of Western music, leading to the complex vocal arrangements seen in later periods.

Monophony, while an important early music style consisting of a single melodic line without harmony, does not reflect the characteristics of music with multiple voices singing in harmony. Homophony involves a primary melody accompanied by chords, rather than independent melodies. Chordal music refers more broadly to music constructed around chords, but does not specifically address the interplay of independent vocal lines that defines polyphonic structure.