For me personally I would say artist like THE ROSE, BTS, and WOODZ.
All of the music they make me feel at peace and nostalgic.
----
As for individual tracks, I have.
BTS - We Are Bulletproof: The Eternal
BTS - Paradise
J-HOPE - Blueside
THE ROSE - She's In The Rain
WOODZ - On My Own
WOODZ - BUMP BUMP
NCT U - Fade In My Last Song
NCT U - From Home
WINNER - BABY BABY
iKON - Why Why Why
TXT - Anti-Romantic
VILLAIN - Piece of Work
----
These are just a few of my favorites. Let me know in the comments your favorites!