Chrismas Music.zip is a release file of the Minecraft resource pack Christmas Music Sound Pack!, made for Minecraft 1.16.4. It was published on December 21, 2020 and is 46 MB in size. For the full description, screenshots and every other version, visit the Christmas Music Sound Pack! resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.