Jongen, considered Belgium's greatest composer since Franck, was greatly influenced by Franck's music early on. He achieved early success in chamber music with a notable piano quartet and a prize-winning 1st string quartet, as well as in several orchestra works, notably the Fantasie on Walloon Christmas Carols op.24. Jongen's compositional style evolved over three periods: the first period demonstrated Franck's cyclic treatment and Fauré's modulations. The second period, around 1910, showed a responsiveness to Debussy's impressionist style, particularly evident in his breakthrough works, the cello sonata (1912) and the Epithalme et Scherzo for three violins and orchestra. His most famous work from this period was the Symphonie Concertante for organ and orchestra. In the third period, from the late thirties, Jongen incorporated aspects of both neo-classicism and modernism, showcased in works such as the Prelude and Chaccone for string quartet op. 101, String Trio op. 135, and the Piano Concerto op. 127. Throughout his style changes, Jongen maintained a consistent blend of form, idea, and craft, ultimately achieving an individual style that deserves broader recognition.
