Preheat the oven to 450 degrees. Sift the flour, baking powder, salt, cream of tarter, sugar, and baking soda. Cut in butter shortening and then add the buttermilk. When dough is no longer sticky, roll out on floured surface. It should be about a half inch thick. Using a circle cookie cutter or large glass, cut out biscuits and then dip both sides in melted butter. Lay dough circles on a baking sheet. Bake for 10-12 minutes.