This arrangement of the hymn Attende Domine is a modern embellishment of the plainchant hymn many of us are familiar with from Lenten liturgies. Some believe the text dates back to 10th Century Spain, though this is uncertain. The melody may be from a different part of Europe and much more recently composed, possibly as late as the early 19th Century.
Even though these words may be over a thousand years old, we have an immediate connection with what they say. This is the consequence of our universal or "catholic" Faith; these truths are unchanging for the people of every generation. The need for mercy and repentance from sin, and our hope in Christ Who has redeemed us, are things we can identify with as strongly as the Christians of medieval Spain. Over the span of time, we see the fulfillment of the prophecy of Psalm 22 (the same Psalm Christ referenced from His Cross): "Men shall tell of the Lord to the coming generation, and proclaim his deliverance to a people yet unborn, that he has wrought it." Though he could not know it at the time, the poet of the 10th Century (or any century) was proclaiming the Faith to a "people yet unborn," that is, us.
The immediacy of Attende Domine is even stronger when we sing it in Latin, the language of the Church. Like the truths of the Faith they express, we know that the Latin words have not changed in a thousand years; the supplication "Attende Domine" is the same one pronounced by the medieval Christian. Our English translation will one day be obsolete as our language changes and develops, but Latin, since it is no longer "living," will remain unchanged. "Attende Domine" can still "tell of the Lord to the coming generation," even if the words "Hear us, O Lord" are no longer understood by then.
Translation
Refrain Hear us, O Lord, and have mercy, Because we have sinned against Thee.
1. To Thee, highest King, Redeemer of all, We lift up our eyes In weeping: Hear, O Christ, the prayers of your servants. Refrain 2. Right hand of the Father, Cornerstone, Way of salvation, Gate of heaven, Wash away our Stains of sin. Refrain 3. We beseech Thee, God, In Thy great majesty: Hear our groans With Thy holy ears: Calmly forgive Our crimes. Refrain 4. To Thee we confess Our sins admitted With a contrite heart We reveal the things hidden: By Thy kindness, O Redeemer, Overlook them. Refrain 5. The Innocent, seized, Not refusing to be led; Condemned by false witnesses On account of impious men Those whom Thou hast redeemed, Keep safe, O Christ. Refrain Translation source: http://www.catholicchant.com/attendedomine.html