Johann Christoph Denner of Nuremburg with the help of his son Jacob improved the chalumeau, creating a new instrument called the clarinet. Denner added two keys to the chalumeau and increased that instruments range by over two octaves. He also created a better mouthpiece and improved the bell (end) of the instrument.
In 1843, the clarinet was further improved when Klose adapted the Boehm flute key system to the clarinet. Mozart was the first composer to use the clarinet in a symphony.