Well, here are some links to some playlists! If you have any game-music or Undertale-related things you'd like to share, then this Forum category/topic is the place!
https://m.youtube.com/playlist?list=PLF4otkmDcK_qHuLO-eO3fm563ZIRM0NUy
https://m.youtube.com/playlist?list=PLF4otkmDcK_qRM2t7BYB0etFJmY_hMtLW
https://m.youtube.com/playlist?list=PLF4otkmDcK_pXwSn5nlSH5uIM1mHCz2vL
Updated by NotMeNotYou