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=USUAN1100671

MacLeod's description:

Genre: Unclassifiable
Length: 4:27
Instruments: harps, voice, exotic organ, waterphone, percussion, glass harmonica

Is she a mer-maid, or is she an illusion! Her enchanting voice will entice, and she is 100% alive! Keep your wits about you, gentlemen - you don't want to be dragged to an unfortunate end.
ISRC: US-UAN-11-00671
Very heavy on bass. Eerie, Intense, Mysterious, Mystical, Relaxed, Suspenseful, Unnerving 2010