Mary Heilmann: Visions, Waves and Road: Abstract paintings by preeminent American artist whose work straddles the geometries of Minimalis m with the spontaneous ethos of the Beat Generation. Until 5 April http:/ /bit.ly/yLaDMA Michael Raedecker: Subtle and enigmatic works combining mut ed tones of paint and embroidery. Until 5 April http://bit.ly/wjf3sG