Composer, jazz musician, percussionist, teacher. He is the first Icelandic composer who, from the start of his artistic career, has been mainly attracted to jazz. After World War II he played as a vibraphone player in many different Icelandic groups. He was also percussionist in the Iceland Symphony Orchestra for nine years. In 1955 he began studying theory and composition with Jon Thorarinson (b. 1917, a former student of Hindemith at Yale University) and continued his studies in Holland at the Amsterdam Music Conservatory with Ton de Leeuw and Léon Ortel, and at the Institute of Sonology in Utrecht. Since his return to Reykjavik he has worked as a composer, as a jazz musician and also as a teacher at the New School of Music. As a composer, he does not feel particularly attracted to the official music scene. He prefers to compose for the theatre, church, amateur choirs and jazz clubs - for musicians and people who he knows personally and in whom he has confidence. His composition output is comprehenseive and includes 80 pieces. However, he has not composed anything for symphony orchestra. Among his works are: solo songs, choral and organ works, chamber music, pieces for solo instruments (piano, organ, flute, vibraphone, double bass) and jazz-influenced compositions. He also composed music for a number of plays and films. Stylistically, Sveinsson´s music is deeply anchored in the European music tradition of the 20th century. However, his music is also clearly dependent both on Icelandic folk music and literature.