Rautavaara, paraphrasing a statement usually made in reference to American politics, said "If an artist is not a modernist when he is young, he has no heart. And if he is a modernist when he is old, he has no brain." Indeed, Rautavaara's style is rooted in modernism, and his earliest works are in a Nordic folk-derived idiom reminiscent of Bartók. Not surprisingly, his approach shifted more strongly toward serialism after his experiences in Cologne. The political subject matter and often thorny 12-tone writing in Rautavaara's first opera, Kaivos ("The Mine") led the Finnish National Opera to reject the work, but in a revised form Kaivos was aired on national Finnish television in 1963. This helped to establish Rautavaara's reputation in his home country.
By 1970, Rautavaara began to lose interest in the rigorous requirements of serialism. With his next major work, the opera Apollo contra Marsyas, Rautavaara opted for a poly-stylistic approach, utilizing jazz and popular music in an ironic juxtaposition against light Viennese classical music. This breakthrough led to the development of Rautavaara's mature style, in which the music is subservient to the demands of his programmatic concepts, whether political, environmental, social, or spiritual. While Rautavaara's prestige gained ground in Europe throughout the '70s and '80s, it was his Symphony No. 7 "Angel of Light" (1994) that established his international reputation. This appealing and meditative work came as a surprise to many who felt that contemporary composers had grown hopelessly out of touch with the emotional needs of the public.
Rautavaara was a prolific composer with a career spanning seven decades. He created ten operas, of which Thomas (1982-1985), Vincent (1986-1987) and Aleksis Kivi (1995-1996) are the best known. He also produced eight symphonies and many concertos including the popular Cantus Arcticus; Concerto for Birds & Orchestra (1972) and the double bass concerto Angel of Dusk (1980). Rautavaara also composed reams of choral, chamber, and vocal music and a small amount of electronic music. Through working directly from his emotions and not hewing to party line serialism, Einojuhani Rautavaara emerged, in the autumn of his life, as one the major figures in contemporary music worldwide.