Weird, the game should have added that for you. Glad I could help though!

Based on the guide, you're missing the article marker.
Open your stage in the editor, and switch the menu bar up top to the fourth option (should be yellow icons). Place the first one down where you want the display.

Also noticed it won't play all 5 songs currently, so double check the first line of code in update. You should see a 4, make it a 5. That's how you tell the game how many song options there are, so can't hurt to double check it.

Placing the article marker determines where the display shows up on screen, there's no one spot for it, place it wherever you think it looks good.
As for the cover_strip, it changes if the cur_song variable does, so my guess is you missed some code in update so the song is always being randomized. Did you change anything inside update at all?

Oh, I never knew you added this for people to use. That's very cool! I'll make sure to try using this sometime in the future for when I decide to update pre-existing stages I made with Aether variants.

Definitely gonna be using this, lol. Making a stage currently that I really want to have more than 4 songs for, and having people actually be able to see which song it is would be awesome.

thank you for the mod!

https://media.tenor.com/Vz6hNcYp6kEAAAAM/black-guy-poggers-poggers.gif

That's innovative. Hopefully others will follow suit when it comes to advanced custom stages.