Friendly reminder that this Google Chrome Extension exists:
It plays music from animal crossing depending on what time it is, and yes it also plays K.K. Slider songs.
I'm not really sure how to add more music to the list, but I have some for it:
K.K. Ska: https://musescore.com/user/5491926/scores/1602436
K.K. Mambo: https://musescore.com/user/5491926/scores/1595066
Bubblegum K.K.: https://musescore.com/user/5491926/scores/1755976 (unfinished atm)