In the first of his two great concertos for clarinet, Weber's operatic style is evident from the dramatic start in the form of a tragic aria. The delightful final rondo, in the style of an opera buffa cavatina, is preceded by a slow movement that is a clear reminder that Weber was a relative by marriage of Mozart. Not only was Constanze Weber's famous husband (already enjoying legendary status) the role model for Weber's father when he set out to make his son a prodigy, but Mozart's Clarinet Concerto K.622 formed the foundation for much of 19th-century composition for the instrument. The second of his clarinet concertos, in E flat major, is a marked contrast to the first; the more symphonic wind of the first movement is structured in a much more classical style, while still demonstrating the coloraturas and virtuosic leaps and runs of the soloist. Weber composed his only two symphonies at the age of twenty, between 1806 and 1807, while he was at the Court of Karlsruhe in the service of the Duke Eugen of Württemberg-Öls. This short interlude in his life was one that he would later remember as one of the happiest of his career and the only one in which he was not at the front of a stage. In terms of functional purpose, it is natural that Weber did not follow the path of Romanticism in seeking to make symphonies into vehicles of metaphysical messages, or statements of cosmic truths.