Resonance

1. Resonance Resonance is defined as “The reinforcement or prolongation of sound by reflection from a surface or by the synchronous vibration of a neighboring object”. An example of resonance can easily be found in musical instruments of all kinds, ranging from woodwinds to stringed instruments. The mass of a string, the length, and the tension of the string, all dictate what frequency the string will vibrate at and, thus, what pitch of sound will be emitted. The strongest resonance of an instrument is located at the natural harmonics of the instrument, such as the 5th, 7th, and 12th fret of a guitar.

2. Resonance (Cont.) Resonance is the movement up and down or back and forth of an object. This motion is called an oscillation. The higher up on a guitar’s neck one plays, the higher the pitch of the notes will become because the strings length becomes shorter and shorter, causing the oscillations of the strings to increase in rate. Some strings can start oscillating at their fundamental frequencies when other strings are played, just as an E string on a guitar will sound after an A string is plucked.

3. A harmonic is a sinusoidal component of a periodic wave or quantity having a frequency that is an integral multiple of the fundamental frequency by definition. • Harmonics are all periodic at the fundamental frequency, which means the sum of harmonics is also periodic at that frequency. In other words, the second harmonic always has exactly half the wavelength (and twice the frequency) of the fundamental; the third harmonic always has exactly a third of the wavelength (and so three times the frequency) of the fundamental, and so on. This is pictured on the right. Harmonics

4. When a guitar string is plucked, the string vibrates most notably at its fundamental frequency, but simultaneously it also vibrates at all integer multiples of that frequency. The vibration along the entire length of the string is known as the fundamental, while vibrations occurring between points along the string (known as nodes) are referred to as overtones. The fundamental and overtones, when sounded together, are perceived by the listener as a single tone. Guitar Harmonics

5. References “The ABC’s of Resonance.” Intuitor.com. April 2, 1996. web. 2007. <http://www.intuitor.com/resonance/abcRes.html> Schmidt-Jones, Catherine. “Harmonic Series.” Connexions.org. April 13, 2010. Web. May 9, 2010. <http://cnx.org/content/m11118/latest/>