The Lamentations 

The celebration of the Burial of the Divine Body, and the descent of our Lord and Savior Jesus Christ to Hades, is one of the greatest holidays of Christendom in which the mournful Character is evident.

During the celebration the Lamentations are sung.
To the Greek Orthodox people the Lamentations are known as << EPITAPHIOS THRINOS >> and is one of the most beloved ecclesiastical hymns (songs) since this is taught to children in schools and they also have the chance to practice it every year during the celebration as the Lamentations are sung in the churches with the participation of all the congregation.