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=USUAN1100007

MacLeod's description:

Genre: Soundtrack
Length: 3:27
Instruments: Orchestra
Tempo: 58

Very airy and eerie. Based off of a feel of Holst's 'Neptune'. 045
ISRC: US-UAN-11-00007 Eerie, Mystical 2006