The oboe is a 2 foot long black cylinder with metal keys covering its holes, and its mouthpiece uses a double reed, which vibrates when you blow through it. This vibration of the reed makes the air inside the oboe move, and thus creates sound. To play it, hold the oboe upright, blow through the double reed in your mouth, and use both hands to press down on the keys to open and close the holes and change the pitch. There are usually 2 to 4 oboes in an orchestra and they produce a wide range of pitches, from haunting sounds to warm, velvety smooth notes, which make the sound of the oboe very memorable. In addition to playing in the orchestra, the first oboist is also responsible for tuning the orchestra before each concert. Listen for the special note "A" that the oboe plays before the music begins.
Despite its name, it isn't English and it isn't a horn. The English horn is actually closely related to the oboe, also uses a double reed, and is played in the same manner. It's longer than an oboe and its tube is a bit wider. At the bottom end of the English horn it opens out into a rounded bell shape, which gives it a warmer, fuller sound. Because it's larger, the English horn also has a lower pitch range than an oboe. An oboe player will also play English horn if it is needed.