A sequence (Latin: sequentia, plural: sequentiae) is a chant or hymn sung or recited during the liturgical celebration of the Eucharist for many Christian denominations, before the proclamation of the Gospel. By the time of the Council of Trent (1543–1563) there were sequences for many feasts in the Church's year.
The sequence had always been sung directly before the Gospel, after the Alleluia.[1] The 2002 edition of the General Instruction of the Roman Missal, however, reversed the order and places the sequence before the Alleluia.[2]
The form of this chant inspired a genre of Latin poetry written in a non-classical metre, often on a sacred Christian subject, which is also called a sequence.