This recording captures it best: The Zähren aria in Bach's St. Matthew Passion - it is sung in the moment after the treason of Peter, when he collapses in tears at cockcrow. There is a minimum of text: "Erbarme Dich, mein Gott, um meiner Zähren willen! Schaue mich! Herz und Augen weint vor Dir bitterlich. Erbarme Dich, erbarme Dich! - Have mercy, my God, For the sake of my tears. Look at me - heart and eyes weeps bitterly before you. Have mercy, have mercy!" For me, this is the emotional heart and soul of the entire passion story, and sometimes I get the feeling it was for Bach, too.
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