Anyone have a parent that constantly hums the same song over and over? I realize that there are much more irritating behaviors.....Ideas?

Yikes, don't really choose Bananaphone either, I was only joking! Polar, it's notorious as an 'earwig' - gets into your head and will not leave no matter what you do.

earplugs.

A few ideas
--get used to it
--teach her another song (which you like)
--wear ear plugs
--keep a distance