My favourite exhibitions over the past year were notable for serendipitous encounters with artists both familiar and new to me. Marsden Hartley's show at Berlin’s Neue Nationalgalerie, Die deutschen Bilder 1913-1915, for example, was one such surprise. His brightly coloured paintings – often of collaged military insignia – reflected the formative years the American modernist painter spent in Europe. Yet the artist’s estranged sexuality was an underlying subtext, and his love for the soldier Karl von Freybourg, who died in the First World War, is evident in Portrait of a German Officer (1914); the centerpiece of this touchingly put together show. Also in Berlin, Marc Camille Chaimowicz turned Galerie Neu’s new space into an aviary for his show Forty by Forty, which featured the artist’s bespoke Italian-designed vases together with utilitarian pieces by Klara Lidén and Manfred Pernice – all of which played host to forty canaries who inhabited the exhibition throughout its duration. In a dilapidated altbau in Kreuzberg, Isabella Bortolozzi Galerie displayed a series of sado-erotic drawings by Pierre Klossowski. Hanging on crumbling walls, or in front of casually draped black cloth, a faint air of decadence lingered in and around the apartment, which became a theatrical set piece for Klossowski’s dubious scenes of illicit activity. This incredible show created a lasting impression.