Musical Instruments

By: Macy Diehl

Stringed Instruments

Violin frequency depends on the length of the string and the tension applied to the string. Whenever the musician places a finger on a string, he changes the length of the string. By doing so, the musician is able to control the vibrating frequency of the string. So if the musician was to place a finger one whole fraction of the length of the string, he would produce a note that is in harmony with the fundamental note. When the bow is moved across the strings, the sound waves produced are not only transversal and longitudinal but also torsion which modifies the timbre of the violin. The resonant box, type of wood, and the varnish used are all major contributors to the sound perceived by a listener when the violin is played. Since the violin can change its sound by simply pushing down on the string, which creates a sharper sound, the musician and the violin have an unlimited range that can be played; however the difficulty of learning the violin is very intense.

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The guitar pitch of a vibrating string depend on mass of string, length of string, tension of string, and the mode of vibration. The mass of the string affect the sound produced by the guitar. A thicker string will produce a lower tone which is why most guitars start with the thinner strings on the bottom working their way up to the thicker strings. Alone a guitar string will not make a very loud noise because it is such a small surface. Since the string is so thin, it does not create a very large disturbance in the air molecules surrounding the string. In order to create a louder noise, the string is surrounded by a larger object with a greater area than the string. The object is usually called the wooden sound box. When the string is plucked or strummed the vibrations created by the string make the box to vibrate at the same frequency as the string. Since the sound box is much larger than the thin string, the box forces the surrounding air molecules to vibrate more intensely because it has a larger surface area in turn creating a louder sound.

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Percussion Instruments

The piano sound heard is produced by vibrating strings inside of the piano. The length, diameter, tension, and density of the wire all affect the sound heard by the listener. Like a guitar, the thinner wires produce a lighter, higher sound. Each note is created by three strings vibrating at the same exact frequency when struck by the hammer. Just like in the violin and the guitar, the length of the string affects the sound produced. The object that causes the strings is the hammer. When the key is pressed down the hammer quickly strikes the string directly above it. The hammer has a very quick tap to the string so it will not affect the loudness of the sound produced. Even when the note is held, the hammer is not directly touching the key but rather suspended in the air right below the string. Now don't think of the hammer as a metal hammer used in construction but rather a small mallet that is heavily padded with felt, which helps soften the strike when the hammer hits the string. The piano also has a soundboard, which acts like the sound box of a guitar and violin. The soundboard has wooden ribs glued across it. These ribs help spread out the sound produced by the strings in turn creating a louder sound when playing the piano. Another key part of the piano is the frame. Many pianos have a tremendous amount of string tension, for example a concert piano has a string tension of about 30 tons! In order to maintain this tension, a piano has a very large and sturdy frame that usually has a large metal plate that the strings attach to. This metal plate is the resonance of part of the tone a listener hears.

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Drums are another great percussion instrument. Although they are categorized with pianos, drums are very different when it comes to both playing and how the sound is produced. The drum and the piano are obviously very different instruments. Instead of a hammer striking a string, a drum is simply a stretched material attached to a hollow base. When this stretched material is hit with either a hand or a mallet/stick it creates a sound. How does this happen? Well when a person strikes the drum, the vibration of the vibrating material reflects onto the air molecule causing them to vibrate at the same frequency. In order to get a different sound produced by a drum, the drummer must take in the type of drum, the shape and the construction of the drum shell, the type of drum heads, and the tension of the drum heads. A tympani drum can be adjusted to give a different pitch by either loosening or tightening the drum head. Think of a rocker star's drum set. It contains multiple drums attached all together. The larger drum is the bass kick and produces a very low sound because it has a larger drum shell. The snare drum is a unique drum because it is not the drum itself that produces the sound but rather the rows of small chains underneath the drum that rattle from the vibrations created when the drum is struck. When the drummer strickes the snare drum, the listener hears a combination of both a drum thud and the rattle of the chains, creating the snare sound. Also on a drum set are the toms. These are similar to the bass drum but have a thinner drum head. Each tom is a different size. Smaller toms create a higher pitch while the larger toms create a sound deep like the bass. Toms are used mostly for "drum rolling" in rock songs.

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