An AppleScript Menu is available in Music by V 1.1.2.28
You need merely Create a "Music" folder in your user Library, put a Scripts folder inside it, and put a script inside that folder, eg: /Users/xxx/Library/Music/Scripts/Adrenergy.scpt
The script is "Adrenergy.scpt"
Next time you open Music "Adrenergy" will show up in a newly revealed Script Menu.
I've used this for years under iTunes to
assign Keyboard shortcuts to my playlists, through System prefs, keyboard shortcuts. It looks like getting that to work under Big Sur and Music will only require twiddling with a few lines of code.
What I'm talking about:
View attachment 1723663
Those are playlist shortcuts in that Menu. I got one to work under Big Sur/Music this morning.
I use them via my Bluetooth keyboard from across the room.