Allan Pettersson holds a unique place in 20th-century Swedish music, having composed sixteen symphonies at a time when many declared the genre exhausted. His Symphony No. 5 (1960-62) unfolds in a single sweeping movement of nearly three-quarters of an hour, its material growing from a four-note chromatic cell through introduction, development and coda. The Malmo Symphony Orchestra performs under Moshe Atzmon, the Hungarian-born conductor's first recording for BIS. The disc also brings Pettersson's haunting Viola Concerto, a deeply personal late work found among his papers after his death in 1980 and not premiered until 1988. Violist Nobuko Imai, winner of top prizes at the Munich and Geneva competitions, is joined here by the Malmo Symphony Orchestra under Lev Markiz.