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=USUAN1100415

MacLeod's description:

Genre: Classical
Length: 0:41
Instruments: Pipe Organ

A very short fugal theme. (3-part imitative counterpoint)
ISRC: US-UAN-11-00415
Dark, Intense, Mysterious 2008