Music by Kevin MacLeod. Available under the Creative Commons Attribution 3.0 Unported license. Download link: https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100355

MacLeod's description:

Genre: Soundtrack
Length: 4:53
Instruments: Pipe Organ, Percussion, Choir, Oboe, Tubas, Trombones, Chimes, French Horns
Tempo: 90

Deep dark background undercurrent. 006
ISRC: US-UAN-11-00355
Dark, Eerie, Epic, Mysterious 2007