"Portum in Ultimo", 12th century (attributed to Bishop Ato of Troyes, dates unknown)

This early example of polyphony, a multivoice piece with independent melody lines coming together to form a cohesive musical sound, is found in the Codex Calixtinus, a manuscript in five volumes dating from around 1140 that includes stories and music celebrating the Feast of Saint Iago, or Saint James, the patron saint of Spain. The manuscript is kept in the Cathedral of Santiago in Compostela. The text of this beautiful piece takes the form of a prayer, asking Saint James to help the recently deceased purge their sins so that they may enter paradise.