Nielsen’s Clarinet Concerto is his last large-scale orchestral work, yet it has received considerably less analytical attention than his symphonies. This is partly because of the problematic generic status of the twentieth-century concerto, but also because of the work’s unusually complex musical language. In this paper, I outline an analytical technology for the work that builds on the notion of dialogue inherent within the concerto form. Nielsen’s concerto raises dialogue to the highest level of structure, and offers one of his most compelling and original musical narratives.