Carl August Nielsen widely recognised as Denmark's greatest composer, was also a conductor and a violinist. Nielsen is best known for his six symphonies. Other well-known pieces are the incidental music for Adam Oehlenschläger's drama Aladdin, the operas Saul og David and Maskarade, the three concertos for violin, flute and clarinet, the Wind Quintet, and the Helios Overture, which depicts the passage of the sun in the sky from dawn to nightfall. Most Danes can sing many of the numerous songs by various poets, set to music by Carl Nielsen. The music initially had a neo-classical sound but became increasingly modern as Nielsen developed his own approach to what Robert Simpson called progressive tonality, moving from one key to another. Typically, he would end on a different key, sometimes as the outcome of a struggle as in his symphonies. His frequently blended melodic passages inspired by folk music with more complicated stylings including counterpoint and modern variations. Like his contemporary, the Finn Jean Sibelius, he studied Renaissance polyphony closely, which accounts for much of the melodic and harmonic "feel" of his music.