Nielsen was born in Sortelung, not far from the city of Odense. His father was a housepainter and amateur musician. Carl first discovered music by experimenting with the different sounds and pitches he heard when striking the logs in a pile of firewood behind his home. His family was relatively poor, but he was still able to learn the violin and piano as a child. He also learnt how to play brass instruments, which led to a job as a bugler in a military band in Odense. He later studied violin and music theory at the Copenhagen Conservatory, but never took formal lessons in composition. Nonetheless, he began to compose. At first, he did not gain enough recognition for his works to support him and in the concert which saw the premiere of his first symphony on March 14, 1894, conducted by Johan Svendsen, he played in the second violin section of the orchestra. However, the same symphony was a great success when played in Berlin in 1896, and from then his fame grew.
He continued to play the violin at the Royal Theatre in Copenhagen until 1905, by which time he had found a publisher for his compositions. In 1916 he took a post teaching at the Royal Danish Conservatory in Copenhagen, and continued to work there until his death.
On April 10, 1891 Nielsen married the Danish sculptress Anne Marie Brodersen. They had met just a month before in Paris. The couple spent their honeymoon in Italy. They remained married until Nielsen's death, despite a long period of marital strife including a lengthy separation and mutual accusations of infidelity.
Music
Internationally, Nielsen is best known for his six symphonies. Other well-known pieces of his are the incidental music for Oehlenschläger's drama Aladdin, the operas Saul og David and Maskarade, the concerti for flute and for clarinet, and the wind quintet. In Denmark, everybody knows and sings the numerous songs by various poets, set to music by Carl Nielsen.
Nielsen's works are sometimes referred to by FS numbers, from the 1965 catalog compiled by Dan Fog and Torben Schousboe.
Symphonies
Nielsen's early Symphony No. 1 in G minor already shows his individuality and hints at what Robert Simpson calls "progressive tonality", by which he refers to Nielsen's habit of beginning a work in one key and ending in another. It was written during, and shares some qualities with, the Holstein songs of opus 10.
A painting Nielsen saw at an inn, depicting the four temperaments (choleric, melancholic, phlegmatic and sanguine) inspired him to write Symphony No. 2, "The Four Temperaments". It is in four movements, each depicting one of the temperaments, but despite this apparent tendency toward being a suite of tone poems, it is a fully integrated symphony. It is not true "program music" but rather a group of general character sketches, and one need not know which temperament Nielsen is considering in order to appreciate the work as a whole.
Symphony No. 3, "Espansiva" was premiered in the same concert as the Violin Concerto. The second movement contains wordless solos for soprano and baritone voices (which can be alternatively played by clarinet and trombone).
Perhaps the best known of Nielsen's Symphonies is Symphony No. 4, "Inextinguishable". It is in four connected movements and is the most dramatic Nielsen had written to date. In the last movement two sets of timpani are placed on opposite sides of the stage for a sort of musical duel.
Symphony No. 5 is one of only two of Nielsen's symphonies that lack a subtitle (which for Nielsen in any case are only very general signposts of intent, not indicating specific story-telling qualities). Like No. 4, it has very dramatic use of percussion: at one point in the second main part of the first movement – which itself consists of two large structures joined to one another – the snare drummer is instructed to improvise "as if at all costs to stop the progress of the orchestra." This symphony is the one by which Nielsen's music made its first significant impact outside Scandinavia, when the Danish Radio Symphony performed it at the 1950 Edinburgh Festival in Scotland where it caused a sensation.
Even Robert Simpson was at first confused by Nielsen's Symphony No. 6, "Semplice". It is not as obviously dramatic as the previous two and in some ways it strikes listeners as strange. For instance, the second movement is only scored for nine instruments of the orchestra (piccolo, 2 clarinets, 2 bassoons, trombone, and percussion) and represents Nielsen's commentary on trends in modern musical composition at the time (the mid-1920's). It is by far the most elusive of his symphonies to grasp, yet its very subtle architectural structure coupled with its enigmatic emotional tone make it a challenging, fascinating, and ultimately rewarding listening experience.
Nielsen's approach to sonata form as seen in his symphonies is one of gradual abandonment. In considering the first movements of each symphony in turn, the first two reveal Nielsen working fairly comfortably within the confines of sonata form as 19th century composers saw it; the middle two include certain high-level references to sonata form but little of the detail, and the last two inhabit a completely new world of Nielsen's own devising, wherein the structure of the movement can only be understood within the context of the material he is working with. By that point in his output there are no more parallels with any other forms or past traditions of musical construction.