I've been thinking about instruments a lot lately and have two projects I want to work on at some point.

Woodwindharpas

I saw a nyckelharpa a few weeks ago, and really liked the idea of simpathy strings. A keyed fiddle doesn't really interest me too much, but adding sympathy strings to arbitrary instruments does. Particularly woodwinds, on the inside. A fluteharpa or clarinetharpa would be really cool. Now if only I could play them.

I might have to settle for a recorderharpa.

Tracheotomal Woodwind Support System

I wanted to make a bagflute. But attaching a bag system to a flute keeps people from being able to control the sound properly with embouchure. No tounging either. So you can't pipe the air directly into the flute. What you really want is to put the air in somewhere before the whole oral cavity. Hence the "tracheotomal". You find someone with a tracheomy and pipe the air in there. Or you smoke for years, get throat cancer, and get your HMO to buy one for you. Regardless of how you get the appropriate hole, with a foot powered bellows and a bag under your other foot you can play without taking breaths.