Also, the text of the chant itself is no cakewalk either. I'd encourage you to check out the english translation below. This is yet another reason that I love the Extraordinary Form: This is sung before the gospel at every EF funeral Mass or Mass for the dead.
Day of wrath and doom impending,
David’s word with Sibyl’s blending,
Heaven and earth in ashes ending!
Oh, what fear man's bosom rendeth,
When from heaven the Judge descendeth,
On whose sentence all dependeth.
Wondrous sound the trumpet flingeth;
Through earth's sepulchres it ringeth;
All before the throne it bringeth.
Death is struck, and nature quaking,
All creation is awaking,
To its Judge an answer making.
Lo! the book, exactly worded,
Wherein all hath been recorded:
Thence shall judgement be awarded.
When the Judge his seat attaineth,
And each hidden deed arraigneth,
Nothing unavenged remaineth.
What shall I, frail man, be pleading?
Who for me be interceding,
When the just are mercy needing?
King of Majesty tremendous,
Who dost free salvation send us,
Fount of pity, then befriend us!
Think, kind Jesu!–my salvation
Caused thy wondrous Incarnation;
Leave me not to reprobation!
Faint and weary, Thou hast sought me,
On the Cross of suffering bought me.
Shall such grace be vainly brought me?
Righteous Judge! for sin's pollution
Grant Thy gift of absolution,
Ere the day of retribution.
Guilty, now I pour my moaning,
All my shame with anguish owning;
Spare, O God, Thy suppliant groaning!
Through the sinful woman shriven,
Through the dying Thief forgiven,
Thou to me a hope hast given.
Worthless are my prayers and sighing,
Yet, Good Lord, in grace complying,
Rescue me from fires undying!
With Thy sheep a place provide me,
From the goats afar divide me,
To Thy right hand do Thou guide me.
While the wicked are confounded,
Doomed to flames of woe unbounded
Call me with thy saints surrounded.
Low I kneel, with heart submission,
See, like ashes, my contrition;
Help me in my last condition.
Ah! that day of tears and mourning!
From the dust of earth returning
Man for judgement must prepare him;
Spare, O God, in mercy spare him!
Lord, all-pitying, Jesus blest,
Grant them thine eternal rest. Amen.