Describe the solution you'd like
Implementation of a means of making music play in areas designated by Areas by Serilium and MapFrontiers by meme_sapiens. Areas allows the player to create zones based on a radius from a special sign. MapFrontiers is an addon to JourneyMap that will likely get a 1.16 update soon, based on activity in that mod's discord, it allows players to slice up their worldmap into regions, and give them names + colors.

Allowing players to assign music to these zones rather than having to do the current method could be a nice option to have. Allowing for the title cards to be triggered in this same way (assuming they will ever make a return), would also be great.

Describe alternatives you've considered
I have been unable to find any practical way to recreate this sort of concept with any other mod or tool.