string theory

Examples of string theory in the following topics:

• Symmetry and Centricity

  • In the passage below—from Bartók's Music for Strings, Percussion, and Celesta—the third violin (3.
  • Below, you'll see the same gesture in the lower strings.
  • As above the lower strings have an ascending gesture that mirrors the descending gesture in the upper strings.

• Playing Harmonics on Strings

  • String players also use harmonics, although not as much as brass players.
  • Harmonics on strings have a very different timbre from ordinary string sounds.
  • Normally a string player holds a string down very tightly.
  • This shortens the length of the vibrating part of the string, in effect making a (temporarily) shorter vibrating string, which has its own full set of harmonics.
  • The length of the string does not change.

• Standing Waves in Wind Instruments

  • The string disturbs the air molecules around it as it vibrates, producing sound waves in the air.
  • The standing waves in a wind instrument are a little different from a vibrating string.
  • The wave on a string is a transverse wave, moving the string back and forth, rather than moving up and down along the string.
  • For the purposes of understanding music theory, however, the important thing about standing waves in winds is this: the harmonic series they produce is essentially the same as the harmonic series on a string.

• de Broglie and the Bohr Model

  • When an electron is bound to an atom, its wavelength must fit into a small space, something like a standing wave on a string.
  • The new theory was proposed by Werner Heisenberg.
  • By different reasoning, another form of the same theory, wave mechanics, was discovered independently by Austrian physicist Erwin Schrödinger.
  • (a) Waves on a string have a wavelength related to the length of the string, allowing them to interfere constructively.
  • (b) If we imagine the string bent into a closed circle, we get a rough idea of how electrons in circular orbits can interfere constructively.

• Standing Waves on Strings

  • Instruments that produce sound using strings are called chordophones, or simply strings.
  • They are what gives the string its rich, musical, string-like sound - its timbre.
  • When the string player puts a finger down tightly on the string,
  • The whole string can vibrate back and forth.
  • But any wavelength that doesn't have a node at each end of the string, can't make a standing wave on the string.

• Rhythm

  • The main purpose of music theory is to describe various pieces of music in terms of their similarities and differences in these elements, and music is usually grouped into genres based on similarities in all or most elements.
  • Because harmony is the most highly developed aspect of Western music, music theory tends to focus almost exclusively on melody and harmony.
  • The rhythm section almost always includes a percussionist (usually on a drum set) and a bass player (usually playing a plucked string bass of some kind).
  • It may also include a piano and/or other keyboard players, more percussionists, and one or more guitar players or other strummed or plucked strings.
  • Vocalists, wind instruments, and bowed strings are usually not part of the rhythm section.

• The Speed of a Wave on a String

  • Imagine you are holding one end of a string, and the other end is secured and the string is pulled tight.
  • Now, if you were to flick the string either up and down.
  • Another example of waves on strings are of the waves on vibrating strings, such as in musical instruments.
  • Pianos and guitars both use vibrating strings to produce music.
  • The speed of a wave on this kind of string is proportional to the square root of the tension in the string and inversely proportional to the square root of the linear density of the string:$v=\sqrt{\frac{T}{\mu}}$

• Sound Production: Vibrating String and Air Columns

  • A vibrating string or air column can both create music and have unique properties.
  • There are many instruments that produce sound based on strings.
  • These sounds are produced by standing waves in the strings.
  • Vibration, standing waves in a string.
  • Calculate the frequency of the sound wave produced by the string and a column of air

• Standing Waves and Resonance

  • Standing waves are found on the strings of musical instruments and are due to reflections of waves from the ends of the string. shows seven standing waves that can be created on a string that is fixed at both ends.
  • The fixed ends of strings must be nodes, too, because the string cannot move there.
  • Standing waves on strings have a frequency that is related to the propagation speed vw of the disturbance on the string.
  • The wavelength λ is determined by the distance between the points where the string is fixed in place.
  • Standing waves in a string, the fundamental mode and the first six overtones.

• Standing Waves on a String

  • When you pluck a string, it appears to vibrate.
  • This is the basis not only for a guitar, but any other string instrument.
  • There are two scenarios of waves in strings: the string is fixed at both ends, or the string is fixed at one end and free at the other.
  • A transverse wave will move along the string until it reaches the other end.
  • When we observe a standing wave on strings, it appears the wave is not moving but standing still.