How was polyphony most often performed?

In music, polyphony is a type of musical texture consisting of two or more simultaneous lines of independent melody, as opposed to a musical texture with just one voice, monophony, or a texture with one dominant melodic voice accompanied by chords, which is called homophony.

Polyphony is often performed to the text of a song.

Explanation:

The inscription is believed to date back to the start of the 10th century and is the setting of a short chant dedicated to Boniface, patron Saint of Germany. It is the earliest practical example of a piece of polyphonic music - the term given to music that combines more than one independent melody - ever discovered.