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=USUAN1100268

MacLeod's description:

Genre: Soundtrack
Length: 0:44
Instruments: Bass, Cello, Viola, Xylophone
Tempo: 108

Broad dark sustained chords in the low strings punctuated with slight percussion. 035
ISRC: US-UAN-11-00268
Dark, 2007