ZAIDEO profiles Dave "Chalkmaster" Johnston, master of sidewalk art at Yonge-Dundas Square. We find the Chalkmaster working on Michaelangelo's Delphic Sybil from the ceiling of the Sistine Chapel as he talks about his experience as a self-taught artist and his chemistry with the crowds as a street performer trying to earn his month's rent. br br Dave's website, , is currently down, but will up again within a month or so.