Sunday Song is a term used to describe two different types of religious music. The first is a HYMN, which is a type of song that is typically sung in churches and other places of worship. It usually has a religious theme and is often accompanied by an organ or other musical instrument. The second type of Sunday Song is a PSALM, which is a type of poem or song from the Bible. Psalms are often used in religious services and can be sung or recited.