Brass instruments are also called labrosones, literally meaning "lip-vibrated instruments" (Baines, 1993). Pitch on a brass instrument can be altered by both the length of the tubing and the changing of the player's lip aperture or "embouchure." Brass instruments are defined by how sound is made (buzzing lips), and are not all made of brass. Some are made of wood and leather, while others are made from other metal alloys, such as silver and copper. The brass instruments in this gallery are classified as follows:
Woodwind instruments, much the same as the brass instruments, may be defined as a wind instruments in which compressed or intensified air is injected into a tube or resonator, setting up the vibration that creates sound. The timbre of the sound is basically governed by the generator of sound. Once the differentiation is made in classifying instruments by their generator of sound, other aspects, such as length, size, and shape of the bore and in some cases the mechanism or device used in altering the length of tubing, further separate instruments into sub classes as indicated below for woodwinds:
Keyboard instruments in this collection are the acoustical instruments whereby a mechanism is activated by pressing a key, to pluck or hammer a string, in order to produce a sound from the string. The main plucked instruments include the harpsichord, the virginals, and the spinet. Piano-type instruments, in which the strings are struck, date as far back as Pythagoras’s “monochord,” followed by the medieval clavichord. The Italian instrument maker, Bartolomeo Cristofori di Francesco, who is generally credited as the pioneer of the piano e forte, devised the part of the piano action mechanism that allowed the hammer to fall back into place after it had struck the string and at the same time cause a damper to fall against the struck string to stop the vibration of the string. Hence, the keyboards are divided into two groups – Those that have a plucking mechanism, and those that use a hammer mechanism.
Strings that are non-keyboard stringed instruments are classified in three categories – a) Violins and Lutes, whereby strings are attached to a long neck that extends to or into a sound box that serves as a resonator to the vibrating strings. b) Harps, usually triangular in shape, whereby strings are stretched at an angle and attached between the vertical neck and a horizontal soundboard; and c) Zithers and dulcimers, whereby the strings run parallel to the sound board, which is usually of one continuous shape.
Percussion instruments include those instruments that produce sound by striking, shaking, or scraping an object. These instruments may include idiophones (the object itself is the generator of sound) and membranophones (the generator of sound is a vibrating stretched membrane/skin). Percussion instruments commonly fall into the following four general categories:
Electronic instruments are musical instruments that make sound primarily by way of electrically driven oscillators, such as the theremin or synthesizer. A user interface device is used to control and/or adjust the properties of sound, such as frequency/pitch, intensity/dynamics, tone color/timbre, and/or duration/rhythm of each sound.
Electric instruments are referred to those musical instruments that use electronic circuits to reinforce means of amplification, such as the electric piano, electric guitar, etc. A user interface is used for adjusting the sound.