All About Transposition
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Transposition is the process of shifting the pitch of a song or composition up or down. This has the effect of changing the key of the song.
In popular music, transposition is usually applied to an entire chord chart, by shifting the pitch of all chords within the chart by a certain amount. This can be done by hand, or even mentally by experienced musicians, but using a tool for transposition is the most efficient.
Transposition is useful in a number of scenarios:
- When adjusting a song to a given vocal range. This happens most commonly when a female is performing a song written for a male's voice, or vice-versa.
- To make a song easier to perform on a given instrument. For example, on guitar it is easiest to play in the keys of G, C, D and A. Guitarists frequently use a capo in order to transpose to a more comfortable key. Many electronic keyboards are also able to transpose.
- For some instruments such as the trumpet or the saxophone, the notated pitch is different than the sounded pitch. This helps players switch between different instruments in the same family, because the transposing pitch is carefully chosen so that fingerings that look the same on paper also stay the same when changing instruments.
Transposition for singers
Singers usually transpose songs in order to sing them in a pitch that is more comfortable, or which has a more pleasant quality of sound, or timbre.
When transposing a song written for a singer of the same sex, the change in pitch to reach the singer's comfortable range is not too much - transposing by 3-4 semitones (a minor or major third) is usually enough. The transposition can be done up or down, depending on the song & the singer's voice.
When singing a song written for the opposite sex, bigger transpositions are sometimes required. It is not uncommon to transpose a song by 5-7 semitones (a fourth or a fifth) to reach a comfortable pitch.
Transposing at the octave (12 semitones) is also common. This leads to the singer singing in a higher or lower pitch without having to change the chords. If an octave transposition is too much, it may be useful to transpose the harmony and the melody in opposite directions. For example, a song in the key of A for a male voice might be too low for a woman to sing in the original pitch, but also too high in certain places when transposed up an octave. In this case, it may be useful to transpose the harmony down to F, while transposing the melody upwards to reach the same key. In other words, the harmony is transposed down 4 semitones (a major third) while the melody is transposed up 8 semitones (a minor sixth). This works because the major third is the Inversion of the minor sixth.
Transposition for guitarists
Guitarists can use a capodastro (a capo) to transpose the sounded pitch of their instrument upwards. This also means that the chords the guitarist is playing are lower than what they sound like.
For example, a common progression in C is C Am F G. With a capo on the 4th fret, the sounded chords become E C♯m A B. In this case, is much more comfortable for a guitarist to play with a capo, as it avoids two barre chords (C♯m and B).
The standard tuning of the guitar makes it very to play in certain keys because the guitarist can use open strings (strings that are not fretted down) in their chords. These are called 'open chords', and are amongst the first things that a beginner guitarist learns. Chords with no open strings can be played by pressing multiple strings down with the same finger - these are called barre chords, and they are much more difficult to play.
In ascending order of difficulty, here are the keys that are easiest to play in on the guitar:
- G major / E minor - almost all common chords can be played open, besides the third chord which is Bm
- C major / A minor - almost all common chords are open, besides the fourth chord: F
- D major / B minor - most common chords are open, besides the sixth (Bm) and third (F♯m)
- A major / F♯ minor - all major chords are open, with the minor chords needing a barre - these are the second (Bm), sixth (F♯m) and third (C♯m) chords in the key
If you are playing a certain chord progression and would like to know what the sounded chords are with a capo on a given fret, then you must transpose up by the position of the capo. On the contrary, if you know what chords you would like to sound out, and you need figure out where to put a capo & what chords to play, you must transpose the sounded chords down & place the capo at the fret matching however many steps you have transposed. Chord Chart Memo makes these calculations very easy.
Guitarists also have the option of using alternate tunings. Some popular tunings where transposition is useful are E♭ and D Standard.
E♭ Standard (a.k.a. D♯ Standard) is obtained by tuning all strings of the guitar one semitone lower than standard. This means that the sound of all chords is one semitone lower than what is actually fingered, and if you are looking to sound a certain chord, you must finger it one fret higher than usual.
D Standard is very similar, in that it is tuned one whole tone (two semitones) below Standard. Therefore, sounded chords are one tone lower than what is fingered, and to sound a specific chord the guitarist must transpose the fingering up two frets.
Transposition for pianists
While in theory the piano is equally good at playing in all 12 keys, in practice many players feel more comfortable in certain keys than others. Keyboard players usually start their learning journey using the key of C major, which uses all the white keys. This makes it relatively easy to sight read music. Keys with few accidentals, such as F or G are also not too difficult.
From another point of view, the key of B Major is physically easier to play in than other keys. B major uses all the black keys, which can be reached easily with the the four fingers of the hand, leaving the thumb on the B and E keys. Another very comfortable key is E major, with four black keys. This key is easy to play in for very similar reasons, thanks to the anatomy of the hand.
In the context of pop music, performing pianists and keyboard players are expected to be able to transpose in order to match the range of the singer. Occasionally the singer may want to perform a song one or two semitones lower than usual if their voice is feeling fatigued. This is no problem for a guitarist who is already using a capo, but may pose a challenge on the keys.
Accompanying pianists faced with this challenge may attempt to transpose mentally, or work out the transposed chords beforehand on a piece of paper. However, it is quickest and easiest to use an app to transpose..
Transposing instruments
For some instruments, such as woodwind or brass, music notation is not written in the sounded pitch. This helps musicians who play these instruments to easily switch between instruments of different sizes, as the mapping between music notation and their technique remains the same.
For example, saxophones are tuned in either B♭ or E♭. The most commonly used saxophone is an alto saxophone, tuned to Eb. This means that when a musician is playing C on the alto saxophone, the sounded pitch is Eb. Overall, the alto saxophone sounds a major sixth lower than written (9 semitones).
Therefore, when adapting a chord chart for an alto saxophone, the chart must be transposed up a major sixth to get the desired pitch. Likewise, when adapting a chart meant for saxophone to non-transposing instruments, the chart must be transposed down a major sixth.
For other instruments, charts are available online showing their transposed pitch