Music by Kevin MacLeod (based on Chopin). Available under the Creative Commons Attribution 3.0 Unported license. Download link: https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100577

MacLeod's description:

Genre: Horror
Length: 5:12
Instruments: Synths, Piano
Tempo: 58

This piece contains 2 themes, one in 7/4 time, and another borrowed from Chopin - and set among very disturbing chords. 038
ISRC: US-UAN-11-00577
Dark, Mysterious, Somber 2009