French company Sopro of Marseille has come up with an electronic device that helps singers improve their vocal techniques. The new gadget produces a musical note which the singers then try to imitate. Meanwhile, their vocal cords are illuminated by a lamp which flashes at a rate that matches the target note. This creates a strobe effect which is then picked up by a video camera and displayed. When the singers hit the right notes, the image of the vocal cords freezes. Drifting off tune makes the vocal cords start to move.