Nationalism: Sibelius was deeply inspired by Finnish folk music, and he incorporated many of its elements into his compositions. This helped to create a unique and distinct sound that was both nationalistic and modern.
Orchestration: Sibelius was a master of orchestration, and his music is known for its rich and vibrant sound. He had a deep understanding of the different instruments and their capabilities, and he used them to create a unique and unforgettable sound.
Melodic invention: Sibelius was a gifted melodist, and his music is full of beautiful and memorable melodies. He had a knack for creating melodies that were both simple and sophisticated, and that could be easily remembered and sung by people of all ages.
Symphonic form: Sibelius wrote many symphonies, and he helped to develop the symphonic form in new and innovative ways. His symphonies are typically characterized by their large-scale structure, their use of leitmotifs, and their dramatic and emotional content.
Legacy: Sibelius's music has had a profound impact on the development of classical music, and he is considered one of the most important composers of the 20th century. His music continues to be performed and enjoyed by people all over the world.