Check out the video ... The night before Xmas was filled with choir members from Kanye's Sunday Service, and they sounded amazing.

Kim narrates the vid ... calling the decor "woodsy" and "homey."

Everyone got all gussied up ... no t's or sweats here. Kylie and baby Stormi wore matching custom Ralph & Russo haute couture emerald dresses. BTW ... Travis Scott was there too.

Kendall wore a black column gown with a feathered neck. Khloe was in a gold dress, and Kourtney chose red.