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French company Sopro of Marseille has come up with an electronic device to
help singers improve their technique (EP 865 759). The gadget produces a musical
note which the singer tries 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 picked up by a video camera and displayed. When
the singer hits the right note, the image of the vocal cords freezes. Drifting
off tune makes the image of the vocal cords start to move.