Vespers is the evening prayer service in the Roman Catholic and Eastern Orthodox liturgies of the canonical hours. The word comes from Latin vesper, meaning "evening."

The general structure of the Roman Catholic service of vespers is as follows:

Vespers opens with the singing or chanting of the words, Deus in adiutorium meum intende; Domine ad adiuvandum me festina. (O God, come to my assistance. O Lord, make haste to help me.)
A hymn is then sung;
Anywhere from two to four psalms are then sung, with the psalms concluding in a doxology and answered by an antiphon.
After the psalms, there is a reading from the New Testament.
Following the reading, the participants sing the Magnificat, the canticle of the Blessed Virgin Mary from the Gospel of Luke I:46-55.
Then a litany is recited, the Lord's Prayer, and a closing prayer.

The psalms and hymns of the Vespers service have attracted the interest of many composers, including Claudio Monteverdi, Wolfgang Amadeus Mozart, Anton Bruckner, and Sergei Rachmaninoff.

See also: Mass (music); requiem; sacred music; Book of Hours