To suitably synchronize sounding timing of a Karaoke performer and change timing of a lighting state of the illumination device, without being influenced by a type and used years of the illumination device, even when tempo changes in the middle of Karaoke performance.

This invention relates to an optical sensor which detects at least either change of illuminance, and change of colors in light generated from the illumination device, and which outputs a light detection signal. The sounding timing of the Karaoke performer obtained from a beat signal included in a Karaoke performance data, is compared with lighting change timing (for example, lighting on timing) obtained from the light detection signal by a light emission controller. When they do not match, synchronization control for synchronizing the sounding timing and the lighting change timing, is performed by controlling the output timing of the light control signal for changing a lighting state of the illumination device.

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