When the player enters a region with music (a region specified in regions.yml), music from that region will begin playing.

If the music in that region is already playing (in a loop) for the player, when entering that region, nothing happens.

If another song is playing (in a loop) for the player, that song will stop playing and its loop will also stop, and the new song will start playing (in a loop).

If the player leaves the region with music to a region without music, the music will not stop playing, but the loop will end as soon as the music is completed. In other words, the music will play until it ends, and after that it will no longer play for the player. However, if the player returns to a region with music, which has that song as its music, before the current song ends, the loop will not be stopped, and the music will continue playing in a loop for the player.

All that needs to be done is to specify (in the regions.yml) the name of the region, the world name of the region, the name of the song (in texture), the tempo of the song (in ticks), the volume of the sound, and the pitch of the sound.