Parts scored for clarinet were soon found in the music of top notch eighteenth century composers, including Handel, Gluick, and Telemann. The early clarinets were customarily made from boxwood or once in a while plum or pear wood. Rarely, they were made of ivory, and some used a mouthpiece of ebony. The design of the clarinet was more suitable by the tip of the eighteenth century. The two keys gave way to 5 or 6, giving the device more pitch control. Composers and virtuoso performers started to take advantage of one of the crucial signal features of the clarinet, its flexible 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 covered clarinets. The clarinet built further in the 19th century. Its intonation was better by a rearrangement of the holes, more keys were added, and the instrument's range was prolonged. Virtuoso performers toured Europe and influenced composers similar to Spohr and Weber to put in writing clarinet concertos and chamber works.