String bending is a
guitar
The guitar is a stringed musical instrument that is usually fretted (with Fretless guitar, some exceptions) and typically has six or Twelve-string guitar, twelve strings. It is usually held flat against the player's body and played by strumming ...
technique where fretted strings are displaced by application of a
force
In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitu ...
by the fretting fingers in a direction
perpendicular
In geometry, two geometric objects are perpendicular if they intersect at right angles, i.e. at an angle of 90 degrees or π/2 radians. The condition of perpendicularity may be represented graphically using the '' perpendicular symbol'', � ...
to their vibrating length. This has the net effect of increasing the
pitch of a note (or notes as the case may be). String-bending allows exploration of
microtonality and can be used to give a distinctive
vocal
The human voice consists of sound made by a human being using the vocal tract, including talking, singing, laughing, crying, screaming, shouting, humming or yelling. The human voice frequency is specifically a part of human sound producti ...
articulation to
lead guitar
Lead guitar (also known as solo guitar) is a musical part for a guitar in which the guitarist plays melody lines, instrumental fill passages, guitar solos, and occasionally, some riffs and chords within a song structure. The lead is the featur ...
passages.
Technique
String bending is executed by fretting a note on the guitar
fretboard, and then applying a force perpendicular to the length of the fretboard with the fretting hand, displacing the string from its resting vibrating position. This yields a continuous increase in pitch, which can be manipulated by a skillful player to give a singing-like quality to a musical passage. The displacement of the string can be pushed "up" or pulled "down". Bending is an important component in the style of several renowned players, such as
Eric Clapton
Eric Patrick Clapton (born 1945) is an English Rock music, rock and blues guitarist, singer, and songwriter. He is regarded as one of the most successful and influential guitarists in rock music. Clapton ranked second in ''Rolling Stone''s l ...
, who uses copious amounts of string bending to articulate
blues
Blues is a music genre and musical form that originated among African Americans in the Deep South of the United States around the 1860s. Blues has incorporated spiritual (music), spirituals, work songs, field hollers, Ring shout, shouts, cha ...
licks and Buck Trent, who electrified a solid body electric banjo and implemented tuner keys and D and B benders in country music. String-bending
blues-scale guitar solo
A guitar solo is a melody, melodic passage, instrumental section (music), section, or entire piece of music, pre-written (or improvised) to be played on a classical guitar, classical, electric guitar, electric, or acoustic guitar. In 20th and ...
s were used in 1950s
electric blues
Electric blues is blues music distinguished by the use of electric amplification for musical instruments. The guitar was the first instrument to be popularly amplified and used by early pioneers T-Bone Walker in the late 1930s and John Lee Ho ...
music where it was most notably popularized by
B.B. King
Riley B. King (September 16, 1925 – May 14, 2015), known professionally as B.B. King, was an American blues guitarist, singer, songwriter, and record producer. He introduced a sophisticated style of soloing based on fluid string bending, sh ...
, and later
rock music
Rock is a Music genre, genre of popular music that originated in the United States as "rock and roll" in the late 1940s and early 1950s, developing into a range of styles from the mid-1960s, primarily in the United States and the United Kingdo ...
ians adopted the string-bending technique in the 1960s.
[Michael Campbell & James Brody (2007), ''Rock and Roll: An Introduction'']
page 201
/ref>
With the advancement of steel guitars and other stringed instruments, and string bending mechanisms and playing styles, string bending is now a common technique among string players.
Factors influencing string bending
There are numerous mechanical and acoustic properties which heavily influence the resultant pitch from a string bend. Analysis of the physics
Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...
of string bending
suggests that the resultant pitch of a string bent at its midpoint is given by
where ''L'' is the length of the vibrating element, ''T'' is the tension of the string prior to bending, is the bend angle, ''E'' is the Young's Modulus
Young's modulus (or the Young modulus) is a mechanical property of solid materials that measures the tensile or compressive stiffness when the force is applied lengthwise. It is the modulus of elasticity for tension or axial compression. Youn ...
of the string material, ''A'' is the string cross sectional area
Area is the measure of a region's size on a surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while '' surface area'' refers to the area of an open surface or the boundary of a three-di ...
and is the linear density
Linear density is the measure of a quantity of any characteristic value per unit of length. Linear mass density (titer in textile engineering, the amount of mass per unit length) and '' linear charge density'' (the amount of electric charge per ...
of the string material.
Thus, the pitch is not only dependent on the bend angle, but on material properties of the string such as Young's modulus; this may be interpreted as a measure of the stiffness
Stiffness is the extent to which an object resists deformation in response to an applied force.
The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.
Calculations
The stiffness, k, of a ...
of the string. The force required to bend a string at its midpoint to a given angle is given by
It is important to note that the resultant pitch from string bending is not linearly correlated with the bending angle, and so a player's experience and intuition is important for accurate pitch modulation.
See also
* Finger vibrato
* Finger vibrato#Axial pitch-shifting
References
{{Reflist
Guitar performance techniques