if the “character bio” buttons don’t appear, restart the project you might already know how to play incredibox, but just in case if you didn’t know, Drag and drop an icon on a character to have him/her sing. Drag down (or click on) a character to have him/her stop singing.
Use any Music app like bandlab or any Music app. Don't use any AI music app, instead, use any Music app that could work if you're reading this, use the rules of it too understand
