Introduction to Carl Nielsen: Carl Nielsen (Carl Nielsen, June 9, 1865 - October 3, 1931) was the most important Danish composer, violinist, and conductor in the early 20th century. He was born with musical talent and served as the dean of the Copenhagen Conservatoire, the highest music institution in Denmark. Nielsen's works have had a profound impact on music in Denmark and even Northern Europe. His face is on the Danish 100 kronor banknote.