I love any Xmas song covered by pentatonix (and there are a ton!), which is a cappella.

Here’s just one album of Xmas music, to get your rabbit hole going! They are so so amazing.

m.youtube.com/watch?v=EGplqTN58jk

But mostly Xmas shit turns into earworms for me in the middle of summer, so I close all the blinds and watch Xmas movies. Makes it almost possible to forget it’s a billion degrees out.