Kyrie eleison   (Lord, have mercy)
Christe eleison (Christ, have mercy)
Kyrie eleison   (Lord, have mercy)

Words: from the Ordinary of the pre-Vatican II Tridentine Mass
Music: Giovanni Pierluigi da Palestrina (1524-1594)
       from Missa Sine Nomine (Mass without a name)

full score: http://www.cpdl.org/wiki/images/9/9b/Palestrina_missa_sine_nomine_letter.pdf