The Ministar travel guitar by Bob Wiley is like taking only what's essential for the electric guitar to work and making a guitar out of it. However, it seems to work pretty well. Read this great article by Gizmag for more info on Wiley's guitar lineup. Also, a video of the ministar in action:
Here's a clip from the documentary Magic Music From The Telharmonium . The Telharmonium was the first electronic synthesizer complete with a touch sensitive keyboard. Three different versions were built, weighing from 7 tons to almost 200 tons! For those wanting more spoilers, you can read this great synthmuseum.com article about the instrument .
If you've never heard of Bruce Haack , you should check this out. Bruce Haack was a real pioneer of electronic music, making electronic albums starting in the late sixties. The audio not the best but works.
The Ondes Martenot is an old electronic instrument that sounds like the theremin . This guy made his own, modern version of the Martenot, for controlling a Korg Monotribe. Check it out! The post at Hack a Day has some more information for those interested in building their own.
This one is really a strange instrument indeed. I'm not sure I fully understand what the sidrazzi even is. Seems to be on the glitch department. Here's a part of the author's description , though it doesn't help much: The Sidrassi is an Organ, designed to reflect the glory of god with pure triangular voices. But it also allows exploration of the Devils' Tone, which is irrational pitch relationships achieved through analog modulations. And here's the video you're waiting for: