Rued Langgaard (1893-1952) is unique in the history of Danish music - a loner whose music, which has only become generally known in recent years, ranges stylistically from Romantic pastiche to inter-war Modernism. The uniqueness consists of the expressiveness of the music, the visionary ideas and the experimental and sometimes extreme musical forms, which in some cases have turned out to point far beyond the composer's own time. Most stylistic aspects are represented in Langgaard's works for violin and piano, two important representatives of which are presented here: the youthful, classically oriented Sonata No. 1, and the experimental one-movement Sonata No. 2 - one of the composer's major works - with a religious-philosophical programme.