Music by Kevin MacLeod (tune arranged by Edward Barnes). Available under the Creative Commons Attribution 3.0 Unported license. Download link: https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100329 [There are two "Angels We Have Heard on High" songs listed. This is the FIRST one.]

MacLeod's description:

Genre: Holiday
Length: 2:25
Instruments: Clarinet, Horn, Strings

Slow and mellow. 004
ISRC: US-UAN-11-00329
Calming, Dark 2005