A Nursery Rhyme used to convey an underlying sadness and/or creepiness, sometimes made into a theme tune that sounds like a music box that's slightly off key. It's mainly used to indicate someone with a Squicky past, a child molester or other psychosis. Ironically, due to this trope, it's very uncommon for anyone to use nursery music to indicate anything positive anymore, making it a common theme of Grimmification. Examples of Ironic Nursery Tune include: