Cantata: a musical composition, one or more voiced accompanied by instruments. Johann Sebastian Bach wrote the music for over 200 religious cantatas.
Incantation: a use of spells or verbal charms spoken or sung as a part of a ritual of magic. From incantare, "enchant". Abracadabra is an incantation.
Cantor: an official of a Jewish synagogue who sings or chants the music of the services and leads the congregation in prayer. Or singer.
Descant: an additional melody sung above the principal melody. Des = two or apart. The descant is a "second song" apart from the main melody.
