Lacrimosa

Mozart's dates are 1756 to 1791: he was only 35.  Britannica explains:

Wolfgang Amadeus Mozart, in full Johann Chrysostom Wolfgang Amadeus Mozart, baptized as Johannes Chrysostomus Wolfgangus Theophilus Mozart, (born January 27, 1756, Salzburg, archbishopric of Salzburg [Austria]—died December 5, 1791, Vienna), Austrian composer, widely recognized as one of the greatest composers in the history of Western music. With Haydn and Beethoven, he brought to its height the achievement of the Viennese Classical school. Unlike any other composer in musical history, he wrote in all the musical genres of his day and excelled in every one. His taste, his command of form and his range of expression have made him seem the most universal of all composers; yet, it may also be said that his music was written to accommodate the specific tastes of particular audiences.

His middle name is interesting.  One of the students I worked with was a 9th grader by the name of Crisostomo.  Crisostomo didn't talk much in class and didn't socialize much, but he was loved.  The students in his class used to refer to him as Ninja because he would come into class stealthily and sit at his desk without hardly a word.  Then today, eleven years later, I come to learn that his name is ancient Greek for "golden-mouthed."  Briefly, on one day we were reading Act I, Scene I of Romeo & Juliet in groups of four.  Crisostomo was in my group along with two other girl classmates of his.  I was a little anxious because Crisostomo hadn't spoken almost at all in class.  I started the reading aloud in the group.  Then the girl to my left read, then the girl to her left read, and then Crisostomo.  And he began reading, his beautiful tone lifted the importance of the passage above anyone of ours' expectations.  The two girls quickly raised their heads from the text and fixed their eyes wide-eyed on me as Crisostomo,  devouring the text, pressed on with the reading.  My heart swelled.  Not just for his personal accomplishment but that his eloquent reading made the exercise remarkably beautiful.  Okay, enough. 

Lacrimosa is one segment in the 8 sections of Mozart's Requiem, a mass for the dead.  The Lacrimosa is the final segment of the section titled, Sequentia.

from Wikipedia: 

The Lacrimosa (Latin for "weeping/tearful"), also, a name that derives from Our Lady of Sorrows, a title given to The Virgin Mary, is part of the Dies Irae sequence in the Roman Catholic Requiem Mass. Its text comes from the Latin 18th and 19th stanzas of the sequence. Many composers, including Mozart, Berlioz, and Verdi have set the text as a discrete movement of the Requiem. 

The lyrics are in Latin.

Lacrimosa dies illa

Qua resurget ex favilla

Judicandus homo reus.

Huic ergo parce, Deus:

Pie Jesu Domine,

Dona eis requiem. Amen.

Their English translation is here: 

Full of tears will be that day

When from the ashes shall arise 

The guilty man to be judged;

Therefore spare him, O God,

Merciful Lord Jesus,

Grant them eternal rest.  Amen.