Antiphonal psalm that is said or read before the Gospel at Mass. Normally the psalm is taken from the lectionary and has some bearing on the particular text from Scripture. After the second reading and before the Gospel the Alleluia is either sung or read, followed by its appropriate verse. If the Alleluia or the verse before the Gospel is not sung, it may be omitted. Except on Easter Sunday and Whitsunday, the sequences (special festive hymns) are optional.