The two keys gave way to 5 or 6, giving the tool more pitch manage. Composers and virtuoso performers began to exploit probably the most signal features 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 realized its chances as a solo instrument. By 1800, most orchestras covered clarinets. The clarinet developed additional in the nineteenth century. Its intonation was more advantageous by a rearrangement of the holes, more keys were added, and the tool's range was extended. Virtuoso performers toured Europe and influenced composers similar to Spohr and Weber to write clarinet concertos and chamber works. Instruments persevered to be made out of boxwood, though makers experimented with silver and brass as well. Some clarinets were made from 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 nineteenth century. But regularly the favorite material became African blackwood, which is comparable to ebony but less heavy and brittle.