When clocks struck nine across Tehran on Tuesday, the night skies filled with sound in celebration of the 47th year of the Iranian revolution. We listened from our hotel balcony as chants of "God is greatest" rose from rooftops and roared from windows. Fireworks flared in a kaleidoscope of brilliant colours. But this year, in this annual explosion of light and sound, there was a discordant note. We heard "death to the dictator" shouted too from somewhere in the darkness of the city, from the