Music by Kevin MacLeod (original composer: unknown). Available under the Creative Commons Attribution 3.0 Unported license. Download link: https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100679

MacLeod's description:

Genre: Classical
Length: 1:31
Instruments: Choir, Pipe Organ

Just a quick piece from a traditional Latin mass. Lyrics are "Agnus Dei, qui tollis peccata mundi, miserere nobis._. Agnus Dei, qui tollis peccata mundi, dona nobis pacem". For Sopranos and Bass.
ISRC: US-UAN-11-00679
Dark, Epic, Mystical 2010