Music Notification is a neat little mod that makes a toast pop up when music starts.
https://www.curseforge.com/minecraft/mc-mods/music-notification

Example and resource pack location: https://github.com/KosmoMoustache/MusicNotification/blob/main/src/main/resources/assets/musicnotification/musics.json

Applies to Medieval Music too, but I don't want to spam you with issues.

Upon further inspection, just adding the relevant JSON file won't work (as of now).