The Difference Between A Pitch And A Key
If you’re new to music there are so many terms to get your head around and it can be quite confusing. In this article we’ll explain the difference between a pitch and a key. As well as adding some interesting anecdotes along the way.
What Is A Pitch?
The pitch is the position of a particular sound within a range of sounds governed by its frequency. The frequency relates to the frequency of vibration of sound waves producing that pitch. The more vibrations per second, the higher the frequency. Not all pitches are identical, it depends on the accuracy of the tuner.
For instance since 1939, orchestras have generally used the A above middle C as a reference for tuning which means every member of the orchestra sets the A string to vibrate at 440 times per second (also known as Hertz).
This system of tuning is generally accepted for all orchestras however, some orchestras tune that A to 443 hertz to create a brighter sound/mood. All other strings are tuned around the A above middle C so the actual pitch in this case has changed from the standard pitch.
The Rainbow Effect
In a rainbow there are seven distinct colours which are; red, orange, yellow, green, blue, indigo and violet. But within that rainbow all of the colour spectrum is present but we can only see seven colours. If the blue is slightly lighter or darker we still perceive it as blue.
It’s exactly the same with the pitch, there are seven natural notes in music (the white notes on a piano), if they are all tuned to one that’s slightly off we will still hear them as in tune, but the whole instrument will be out of tune with the rest of the band.
What Is A Key?
Musically speaking, a key is a system of related chords (chords that sound good together) revolving around a central note. That central note is known as the keynote or tonic and the central chord is the tonic triad which is built using the tonic note, the third note and the fifth note.
Any one of the twelve notes of the chromatic scale can be used as the keynote or tonic. This means there can be twelve major keys and twelve minor keys and all have been used as the tonic key. On sheet music the key is shown by a series of sharps or flats at the beginning of each staff.
Keys are necessary for the system of tonality to function as it relies on the organisation of notes, chords and keys around the root or tonic note. Some songs or short pieces of music may use only one single key and are therefore said to be in that key. Other longer pieces of music often change keys sometimes on numerous occasions but are usually arranged as to be identified as being in that particular key.
Keys are related depending on how many notes their diatonic scales share. For instance, C major and G major have six of their seven notes in common (the difference being G major has F# as opposed to C major’s F ♮). Whereas C major and C# major have absolutely no notes in common at all.
The Relation Between Major & Minor Scales
The key of C major has absolutely no sharps or flats so the musical signature shows no sharps or flats on sheet music. However, A minor is the relative minor of C major and also shows no sharps or flats. So a piece of music with no sharps or flats could be either C major or A minor.
The relative minor of any major key will show the exact same amount of sharps or flats at the start of the sheet music.
The Difference Between A Pitch & A Key
The pitch is the frequency of the vibration of the sound wave that creates the note. And the key is a system of notes and chords that revolve around a central key, tonic or root note.
Frequently Asked Questions
Although off key and off pitch are used to describe the same thing, they do not actually mean the same thing. Off pitch means that the string and by extension the whole instrument is not resonating at the correct vibrations. Off key implies the instrument being out of tune.
Pitch is the frequency of sound produced when you sing or play an instrument. Notes are the symbols used to indicate the location of the pitch.
C4 is the scientific pitch notation of middle C on a standard 88-key piano. It is called C4 because it is the fourth C note on a standard piano.
C3 is the C note one octave below middle C on a piano.