Weber wrote two Concertos for clarinet and orchestra and also a Concertino (a small concerto in one movement). Another one-movement concerto was the "Konzertstück in F minor" for piano and orchestra. His opera "Der Freischütz " is probably his best work, and the overture is often heard separately as a concert piece. The story of the opera is full of magic. It is written in German and has some spoken words as well as sung music (this kind of opera was called a Singspiel). This opera in particular influenced Richard Wagner who developed German opera in the 19th century.