Silent square dance accompanist.
Because my dad loves to sleep in and is often woken up by square dances during the day on Saturdays and Sundays, he invented this, which has been improved to also convert the audio directly into blinking?
But in terms of practicality, isn't it a strange scene to have a group of people dancing silently around a pillar of light? There's no sense of bandwagon at all, OK?
Sure enough, when my dad gave this invention to the square dance team downstairs, it was politely rejected?