Abstract: An audio signal is connected to one of two orthogonal deflection means on a kinescope and the audio signal phase shifted by 90 degrees is connected to the other deflection means. The phase shift device shifts the phase by 90.degree. at one or more given frequencies and by different amounts at frequencies other than the given frequencies so that the shape of the pattern produced on the kinescope varies with spectral content of input signal. The phase shift device is adjustable to permit selection of the given frequency at which 90.degree. phase shift occurs. A brightness control circuit responds to the audio signal so that the brightness varies with the magnitude of the audio signal. A cathode beam control circuit for blanking the kinescope trace at a rate determined by the amplitude of the audio signal or at a rate determined by an internal osciallator. A counter circuit for use with a tri-color kinescope which switches the three cathode circuits on and off to afford color variation to the pattern.