Trombone
The trombone is a musical instrument in the brass family. Like all brass instruments, it is a lip-reed aerophone: sound is produced when the player’s vibrating lips (embouchure) cause the air column inside the instrument to vibrate. A person who plays the trombone is called a trombonist.
The trombone consists of a cylindrical tube bent into an elongated "S" shape in a complex series of tapers, the smallest being at the mouthpiece receiver, and the largest being at the throat of the bell, before the flare for the bell begins. As with other brass instruments, sound is produced by blowing air through pursed lips producing a vibration that creates a standing wave in the instrument.
The trombone was used frequently in 16th century Venice in canzonas, sonatas, and ecclesiastical works by Andrea Gabrieli and his nephew Giovanni Gabrieli, and also later by Heinrich Schütz in Germany. While the trombone was used continuously in Church music and in some other settings from the time of Claudio Monteverdi onwards, it remained rather rare in the concert hall until the 19th century. During the Baroque period, Johann Sebastian Bach and George Frideric Handel used the trombone on few occasions; Bach used it in combination with the cornett to evoke the stile antico in some of his many cantatas and Handel used it in the Dead March from Saul, Samson, and Israel in Egypt, all of which were examples of a new oratorio style, popular during the early 18th century. Unlike most other brass instruments, the trombone is not usually a transposing instrument. Prior to the invention of valve systems, most brasses were limited to playing one overtone series at a time; altering the pitch of the instrument required manually replacing a section of tubing (called a "crook") or picking up an instrument of different length. Their parts were transposed according to which crook or length-of-instrument they used at any given time, so that a particular note on the staff always corresponded to a particular partial on the instrument. Trombones, on the other hand, have used slides since their inception. As such, they have always been fully chromatic, so no such tradition took hold, and trombone parts have always been notated at concert pitch.