Kevin MacLeod ~ Drone in D

Description YT

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=USUAN1200044

MacLeod's description:

Genre: Contemporary
Length: 21:23
Instruments: Piano, Synth

A very long piece of highly relaxing music - done as mostly a piano impromptu over a simple drone (very long note). The piece is in the key of D... mostly. (usually, there is an F sharp and C sharp - this uses an F sharp and B flat... there is no name for this that I know of)
ISRC: USUAN1200044 Calming, Relaxed 2012