Music to die for
The standby queue for the Haunted Mansion has several items to entertain guests who weren't able to get Fastpasses for the attraction. Among them is this "Ravenscroft" organ which plays spooky music when its keys are touched. I believe that it's loosely modeled after the organ in the ballroom scene. And of course, Ravenscroft is a nod to voice actor Thurl Ravenscroft, who can be seen singing Grim Grinning Ghosts in the graveyard.