This is a list of the
fundamental frequencies
The fundamental frequency, often referred to simply as the ''fundamental'', is defined as the lowest frequency of a periodic waveform. In music, the fundamental is the musical pitch of a note that is perceived as the lowest partial present. I ...
in
hertz (cycles per second) of the keys of a modern 88-key standard or 108-key extended
piano in
twelve-tone equal temperament, with the 49th key, the fifth A (called A
4), tuned to 440 Hz (referred to as
A440 A440 or A-440 may refer to:
* A440 (pitch standard)
* A440 highway (Australia), a road in Victoria, Australia
* Quebec Autoroute 440 (Laval)
* Quebec Autoroute 440 (Quebec City)
See also
* Apollo 440, an English band
* Airbus A400M
The Airb ...
).
Since every octave is made of twelve steps and since a jump of one octave doubles the frequency (for example, the fifth A is 440 Hz and the sixth A is 880 Hz), each successive pitch is derived by multiplying (ascending) or dividing (descending) the frequency of the previous pitch by the
twelfth root of two
The twelfth root of two or \sqrt 2/math> (or equivalently 2^) is an algebraic irrational number, approximately equal to 1.0594631. It is most important in Western music theory, where it represents the frequency ratio ( musical interval) of a se ...
(approximately 1.059463).
For example, to get the
frequency one
semitone up from A
4 (A
4), multiply 440 by the twelfth root of two. To go from A
4 to B
4 (up one
whole tone
In Western music theory, a major second (sometimes also called whole tone or a whole step) is a second spanning two semitones (). A second is a musical interval encompassing two adjacent staff positions (see Interval number for more deta ...
, or two semitones), multiply 440 twice by the twelfth root of two (or once by the sixth root of two, approximately 1.122462). To go from A
4 to C
5 (which is a
minor third
In music theory, a minor third is a musical interval that encompasses three half steps, or semitones. Staff notation represents the minor third as encompassing three staff positions (see: interval number). The minor third is one of two common ...
), multiply 440 three times by the twelfth root of two (or once by the fourth root of two, approximately 1.189207). For other tuning schemes refer to
musical tuning
In music, there are two common meanings for tuning:
* Tuning practice, the act of tuning an instrument or voice.
* Tuning systems, the various systems of pitches used to tune an instrument, and their theoretical bases.
Tuning practice
Tun ...
.
This list of frequencies is for a theoretically ideal piano. On an actual piano the ratio between semitones is slightly larger, especially at the high and low ends, where string stiffness causes
inharmonicity, i.e., the tendency for the
harmonic
A harmonic is a wave with a frequency that is a positive integer multiple of the '' fundamental frequency'', the frequency of the original periodic signal, such as a sinusoidal wave. The original signal is also called the ''1st harmonic'', the ...
makeup of each note to run
sharp
Sharp or SHARP may refer to:
Acronyms
* SHARP (helmet ratings) (Safety Helmet Assessment and Rating Programme), a British motorcycle helmet safety rating scheme
* Self Help Addiction Recovery Program, a charitable organisation founded in 199 ...
. To compensate for this, octaves are tuned slightly wide,
stretched according to the inharmonic characteristics of each instrument. This deviation from equal temperament is called the
Railsback curve
Piano acoustics is the set of physical properties of the piano that affect its sound. It is an area of study within musical acoustics.
String length, mass and tension
The strings of a piano vary in thickness, and therefore in mass per length, ...
.
The following equation gives the frequency of the
th key, as shown in the table:
:
(a' = A
4 = A440 is the 49th key on the idealized standard piano)
Alternatively, this can be written as:
:
Conversely, starting from a frequency on the idealized standard piano tuned to A440, one obtains the key number by:
:
List
Values in bold are exact on an ideal piano. Keys shaded gray are rare and only appear on extended pianos. The normally included 88 keys have been numbered 1–88, with the extra low keys numbered 89–97 and the extra high keys numbered 98–108. (A 108-key piano that extends from C
0 to B
8 was first built in 2018 by
Stuart & Sons.
)
See also
*
Piano tuning
*
Scientific pitch notation
Scientific pitch notation (SPN), also known as American standard pitch notation (ASPN) and international pitch notation (IPN), is a method of specifying musical pitch by combining a musical note name (with accidental if needed) and a number ide ...
*
Music and mathematics
References
External links
interactive piano frequency table– A PHP script allowing the reference pitch of A4 to be altered from 440 Hz.
PySynth– A simple
Python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (pr ...
-based
software synthesizer that prints the key frequencies table and then creates a few demo songs based on that table.
*
Keyboard and frequencies, ''SengpielAudio.com''.
Notefreqs– A complete table of note frequencies and ratios for midi, piano, guitar, bass, and violin. Includes fret measurements (in cm and inches) for building instruments.
{{Pitch (music)
Piano
Musical tuning