Clarinet is the most important woodwind in the orchestra, and has a very wide range. It has 18 holes, six of which are covered by fingers and the remainder by keys. The pitch of the tone is determined by covering the holes.
Clarinets used to all be made of wood but now many are made of ebonite. All have single reeds. There are thirteen different types of clarinets, but the most common in orchestras are the B-flat for the keys with flats and the A for the keys with sharps. Clarinets have a smooth, even sound, which makes them compatible with most orchestral instruments. They can play many different moods, and can play very loud or very soft. Because of this, in military bands a clarinet plays the role of the violin. If an orchestra requires a saxophone, and one is not available, a clarinet could play that role also. The lower-sounding clarinets (like the alto, bass and contrabass) have upturned metal bells, which cause them to resemble a saxophone in appearance. The bass clarinet is comparable to the cello in pitch.
In the late 1600?s, a company in Germany developed an instrument which was the beginning of the clarinet. It had a tone like a small trumpet, and acquired the name "clarinet". In about 100 years, lower-pitched clarinets existed. Mozart loved the clarinet, and brought it into popularity in orchestral music. He wrote important solo works for it and included it in several orchestral pieces. It continued to be refined, by adding more keys to improve its range and tone.
The bass clarinet was perfected by Adolphe Sax in 1840, who invented the saxophone. This is the reason the two are very similar.
List of books: Clarinet