Symphony No. 7 in C major was his last published symphony. Completed in 1924, it is notable for having only one movement. It has been described as "completely original in form, subtle in its handling of tempi, individual in its treatment of key and wholly organic in growth". It has also been called "Sibelius's most remarkable compositional achievement". Initially titled "Fantasia sinfonica", it was first performed in Stockholm in March 1924, conducted by Sibelius. It was based on an adagio movement he had sketched almost ten years earlier. While the strings dominate, there is also a distinctive trombone theme.