Categorize this under Sunday Silliness. Here’s an examples of a project using hat mounted soft sensors to control MIDI on an attached laptop. They are known as MIDI Hats. The hat has sensors made from steel wool embedded in the felt which are connected to an Lilypad Arduino, which in turn communicates with MAX/MSP on the attached laptop.
This project builds on the work of Lara Grant in using soft sensors as musical controllers.
Via Fashiontech.

hm… a 2-person unicorn Halloween costume with a MIDI horn? Pun fully intended!