So in my boring time at work I came across this while surfing the internet. Now I am pretty familiar with music and instruments. I play the piano and played the trumpet in high school. I though I was pretty well educated in many different instruments and new their names. This is a new one for me. It is amazing how she makes the sounds. This instrument is called a Theremin. Read the wiki link to see how they control the sound. This girl playing it is pretty good and it is interesting to see her play it. Check it out.