The principal woodwind instruments of the modern symphony orchestra are the FLUTE, CLARINET, OBOE, and BASSOON. Each of these instruments is the head of a family, or section. The flute family includes the flute and piccolo; the clarinet family includes the clarinet, bass clarinet, and E-flat clarinet; the oboe family includes the oboe and English horn; and the bassoon family includes the bassoon and contrabassoon. The saxophone is also considered a woodwind instrument.
A woodwind instrument is essentially a long tube, or pipe. In order for the instrument to sound, something must make the column of air inside the tube vibrate. The members of the clarinet, oboe, and bassoon families depend on reeds to set the air column vibrating; the player's breath makes the reed itself vibrate. The clarinet uses a single reed, which vibrates against the mouthpiece in which it's set, and the oboe and bassoon both use a double reed, whose split ends vibrate against each other between the player's lips. The members of the flute family are the only woodwind instruments that are not reed instruments. The mouthpiece of a flute is just an oval-shaped hole cut into the side of the instrument near one end. The player blows across (not into) the hole, and the stream of breath strikes the sharp, far edge of the hole, setting up localized air vibrations. These localized vibrations are what set the air column in the instrument vibrating. The same principle applies when blowing across the opening of a bottle to produce a sound.
The modern OBOE most likely originated in France during the 1600s. The word oboe, which is the instrument's name in both English and Italian, comes from the French name, hautbois (pronounced “oh-bwah”), meaning “high wood,”, or “loud wood.” Early English versions included hautboy, howboie, hoyboye, and hoboy. The double-reed forerunner of the oboe was an instrument called the “shawm.”
If the oboe is the soprano and the English born is the alto or tenor, the BASSOON is the bass of the double-reed family. It consists of a long wooden tube constructed with a tight bend so that it doubles back on itself, forming two parallel columns. If it weren't doubled, it would extend to a length of about eight and a half feet and would be impossible to play. The reed isn't inserted directly in the instrument, as on the oboe, but fits on the end of a long, curved metal tube called the crook, or bocal. (The English horn also uses a bocal, but a much shorter one.)
The CLARINET was the last of the principal woodwind instruments to join the orchestra. The modern clarinet evolved from earlier forms in the early 1700s — later than the oboe, bassoon, and flute — and it wasn't until quite late in the century that orchestral composers included it in their scores with any regularity. Of Mozart's forty-one symphonies, for example, only four, Nos. 31 (1778), 35 (1782), 39 (1788), and 40 (1788), include parts for clarinet. All of Beethoven's symphonies, on the other hand, call for a pair of clarinets: by 1800, the clarinet was in the orchestra to stay.
The SAXOPHONE was invented by the Belgian instrument maker Adolphe Sax (1814–1894) in about 1840. It uses a clarinet-style mouthpiece with a single reed and is generally considered a woodwind instrument, but it's made of brass. It comes in a variety of sizes, the most common of which are the soprano saxophone, alto saxophone, and tenor saxophone. Sax originally intended the instrument for use in military bands, and it became well known in the United States starting in the late 1800s largely through the efforts of the bandmaster John Philip Sousa (1854–1932). Its importance as a jazz instrument dates from the 1920s.Taken from Chicago Symphony Orchestra's website.