Musical instruments fall into four main categories: strings, brass instruments, woodwinds and percussion. Electronic instruments also exist, both as a separate group and as different version of string instruments. Each family of instruments produces sound in a different way.
String instruments produce sound by plucking or sliding a bow across strings. By pressing on the strings, it shortens their length and increases the pitch of the note played. Some examples of string instruments are the violin, guitar, cello, bass and viola. String instruments are most common in orchestras and rock bands.
Brass instruments consist of a coiled tube in which the notes are altered by lengthening or shortening the tube with valves or slides. The air comes from a buzzing sound produces by the player's lips, also known as embouchure. The trumpet, trombone, French horn and tuba are common brass instruments.
Woodwinds usually produce sound when the player blows air across a wooden reed, in conjunction with finger positions on the instrument. Flutes and piccolos do not use reeds. Other woodwinds include the clarinet, saxophone and oboe.
Percussion instruments produce sound by striking a surface with a hand, stick or mallet. Most percussion instruments do not have different tones, except for the xylophone. Some percussion instruments are the bass drum, snare drum, cymbal and gong. Percussion instruments provide tempo for the rest of the ensemble.