The ancient chants of Tenebrae are the Church's song of mourning for her betrayed, crucified, and buried Redeemer.
The Lamentations of Jeremiah are cries from the heart over the ruin of the Jerusalem, and a call to rebuild what is broken. They reflect the sorrow of the Church for her sin.
Excerpt from from Shalom World's special on Tenebrae broadcast on April 18, 2019: kzfaq.info/get/bejne/jbp9o9CIta7Dp2w.html
Order booklets with notation to sing English Tenebrae here: www.birettabooks.com/for-the-priest/tenebrae-service-booklet-good-friday/