The design of the clarinet was superior by the top of the eighteenth century. The two keys gave way to 5 - 6, giving the instrument more pitch control. Composers and virtuoso performers started to exploit one of the crucial signal traits of the clarinet, its versatile dynamic range, from whisper soft to loud and penetrating. Mozart composed a concerto for clarinet in 1791, appearing that he found out its probabilities as a solo instrument. By 1800, most orchestras blanketed clarinets. The clarinet built extra in the nineteenth century. Its intonation was more suitable by a rearrangement of the holes, more keys were added, and the instrument's range was extended. Virtuoso performers toured Europe and prompted composers corresponding to Spohr and Weber to write clarinet concertos and chamber works. Instruments endured to be made from boxwood, though makers experimented with silver and brass as well. Some clarinets were made out of cocuswood, a tropical wood found mostly in Jamaica. French makers began making clarinets out of ebony, a heavy, dark wood from Africa, in the mid 19th century.