Helge Jacobsen was one of the original members of Linien II. He was invited per letter to participate in the important founding meeting in Tivoli Hallen in December 1946 and was among the exhibitors at Linien II's first exhibition in Tokantens Kunsthandel in September 1947. Concrete art has always had a certain anchoring in jazz music, and Helge Jacobsen was in the 40' s and 50s also an active jazz guitarist who performed with Leo Mathisen and Charlie Parker, among others. From having painted fabulous and colour-saturated so-called “jungle fantasies” throughout the 1940s, Jacobsen's expression gradually dissolved into a completely concrete motif. These are tight compositions, but which still through the often mixed choice of media and techniques, cannot hide the artist's natural urge to experiment. Towards the end of the 50s, Helge Jacobsen broke with the concrete artists and became preoccupied with his own freer and more spontaneous abstraction with calligraphic elements and inspiration from Tacism.