Prague Signal light festival celebrates Velvet Revolution At the annual Signal festival of light, video-mapping and digital art focuses on revolution 30 years after the peaceful 1989 Velvet Revolution that toppled a totalitarian Communist regime, which lasted four decades in former Czechoslovakia. The country then went on to split into the Czech Republic and Slovakia four years later. Artists presenting their work at the festival look back at 1989, asking whether people are capable of a revolution now, at a time when mankind experiences unrest and protests. The seventh edition of the festival started Thursday and offers 18 installations in Prague’s historic centre with more than half a million viewers expected over four days.