Jerry Blavat, the fast-talking Philadelphia DJ and impresario known as “The Geator with the Heater,” has died at 82. His tireless promotion of pioneering Black artists of the 1950s and 1960s shaped the pop music culture of the city where he maintained an iconic presence for seven decades. Mr. Blavat first came to fame as a dancer on the teen-targeted pop music television show Bandstand in the 1950s. Having learned to jitterbug watching his mother, aunts, and uncles dance to A