Flash Mob paid tribute to Rhythm Nation this weekend with dancers donning black leather and powerful moves. The Castro was their encore destination in a day of street dance that stopped trains on the tracks.  The ‘F’ line had to pause for the four minute performance much to the delight of passengers.  Who are these impromptu artists?  “We are a fun-loving Flash Mob group who surprises the public with spontaneous performances of choreographed dances all over the SF Bay area,” according to their website.  What makes them especially brilliant is how anybody can join in — and the fact that they get to do it in San Francisco.

Anyone can attend free classes or teach themselves through YouTube video tutorials.  All you have to do on ‘show day’ is dress the part.  And thanks to Facebook updates, you can’t lose track of the next stage.  It was my good fortune to feel the rhythm on the first day of April.