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=USUAN1100653

MacLeod's description:

Genre: Electronica
Length: 10:54
Instruments: Synths

Deep unsettling piece with no repeated themes. Fat, rounded bass drone with very high pitched interest on top.
ISRC: US-UAN-11-00653
Dark, Eerie, Mysterious, Mystical, Unnerving 2009