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What Key Should My Song Be In?

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Read Time: 7 min

Ever wondered what the best key for your song might be? From a practical point of view, the vocal range of your singer will obviously need bearing in mind. But what's the best key for your guitarist or bass player? What other considerations are there? In this tutorial we help choose the perfect key.

“Music can name the unnameable and communicate the unknowable”

– Leonard Bernstein

Let's start with the vocalist. A male singer with a strong tenor range voice might prefer to sing in a key like G or A major, where the natural ‘tessitura’ or range of the melody might often lie above middle C. But your favourite female singer is likely to enjoy working in a lower key, like D—or even C if she is an alto. She won’t want her voice sounding too high and thin!

From an instrumental point of view, both electric and acoustic guitars sound naturally good in keys like E, A and D because their string tunings ‘fit’ well with those keys. On the other hand, in the key of D that low D will be out of range for your 4-string bass player, unless he decides to drop his bottom string tuning, or buy a five string!

More complex still, arranging your piece in certain keys might mean the piano or string inversions you’ve written sound too full, and ‘clog up’ the whole mix. Do you rewrite them, or move the whole piece to a higher key?

Mood Music?

Is there also a mood consideration? Some say that major keys always sound brighter and minor keys more melancholy, but is that always the case? Can major keys sound ‘dark’ sometimes? Are certain minor keys naturally more dramatic than others?

Did you know that ‘All You Need is Love’ was originally written in G major? Would it have been as great a hit if it had been written in Eb? Would Beethoven’s Moonlight Sonata sound the same in B minor as in its actual key of C# minor?

Before we can look at whether keys can affect how bright, dramatic or melancholy your song will sound to others, we’ll need to get a few music theory basics sorted. In this article I propose to look at scales, keys and key signatures and how they relate to each other, and in the following two articles we’ll get on to the harmonic structure of a song.

The Diatonic Scale System

First, a little western music history knowledge. We’re talking exclusively about ‘western music’ here. There are lots of types of world music that don’t involve the diatonic scale, like Arabic music which uses non-western scales, or Indian or Thai traditional music, for example.

Back in the 1600s, some keys contained horrible dissonances because the frequency relationships between the notes in each octave had not been set as identical. The ‘equal tempered’ or ‘well-tempered scale’ changed all that. It defined each semitone as being equidistant in frequency from its neighbour, across the octave. That meant that you could play in any key without fear of grating dissonances.

Bach celebrated this by composing his landmark 48 Preludes and Fugues; 2 written in each major and minor key. Most piano students come across this seminal classical work at some point in their studies.

Major and Minor Scales

As you probably know, there are eight notes in any scale if you count the octave. But if we include every note in between, there are actually 12 semitones or half tones.

So, if we take the key of C, there are actually three main ways of getting from low C to high C; one major scale and two different types of minor scale. You can see them written out below.

Notice the melodic minor scale uses different notes going up and coming down; the sixth and seventh note are raised going up and lowered coming back down. The harmonic minor scale is the same in both directions. The 3rd note is again lowered, but its peculiar feature is the wide gap between the lowered 6th note and the raised 7th.

All scales of CAll scales of CAll scales of C
All scales of C


Accidentals is the collective word for the sharp sign, the flat sign, and the natural sign. A sharp raises the note it precedes by a semitone, a flat lowers it, and a natural sign restores the note to its original state again.

All the black notes of a keyboard are referred to as either sharps or flats, depending on which scale you are in. So E major has four black notes in its scale; F#, G#, C#, and D#. And Bb major has two flats; Bb and Eb.

Technically, any note—white or black—can be a sharp or flat in relation to its neighbour. So the key of F# major has six sharps including E# which is played as an F, though it is a white note.

F# major scaleF# major scaleF# major scale
F# major scale

Note that D# and Eb refer to the same black note on the keyboard in any octave. But before the invention of the well-tempered scale, this wouldn’t necessarily have been the case. The equally distanced diatonic scale system is a kind of harmonic compromise, but at least it means that the seven octave piano doesn’t have to be many times longer than our arms could reach!

Key Signatures

What exactly are key signatures then? They are just a means of shorthand that you can use at the beginning of your piece next to the clef sign.

For example, if you are in the key of G, you know that probably every F you encounter will actually be sharpened to an F#; so why not create a shorthand that tells you that at the beginning of a piece? Then you won’t have to write the sharp sign every time there’s an F.

As we’ve seen, some keys have lots of them; Db has five flats and B has five sharps. As any music student will tell you, that’s a lot of notes to remember to change if you’re trying to play a sight reading piece in an exam!

Here’s a list of all the key signatures. Note that each one can refer to either a major or a minor scale, which is actually known as its relative minor.

All key signaturesAll key signaturesAll key signatures
All key signatures

So How Do They Sound?

It’s often been said that major keys tend to sound happy and positive in mood, but some claim that certain major keys like Db or Ab can sound ‘darker’ than major keys based on white notes on the keyboard. Lots of opinions have been expressed about this through the ages.

Here’s a list of what some have said. See if you agree!

Key descriptionsKey descriptionsKey descriptions

The association of mood with certain keys is a highly subjective area, so I won’t be too surprised if you disagree with anything in the above table. For me, after the practical considerations of instrument and vocal range have been taken care of, it can sometimes be an additional factor to take into account though.

For example, if your piece is in a major key but has a more thought provoking, restful mood, it might benefit if it were moved to a lower key, especially if your singers tone sounds ‘darker’ as a result.

The song ‘Moon River’ from Breakfast at Tiffany’s is a great example of this:

Minor scales can clearly provide lots of scope for emotional pathos and drama. I can think of no better example than the theme from the film ‘Schindler’s List’, which is played by Itzhak Perlman, acknowledged as one of the finest violin players of his generation.

Note the pathos of the falling intervals of the melody as the harmonies work through several related keys to find their way unerringly to the home key of D minor:

YouTube clip featuring Theme from ‘Schindler’s List’


This article is the first of several, in which I aim to take a deeper look at the whole area of music theory and how we can make use of it to write really great songs! Next up, I plan to take a look at the whole area of harmony in two separate articles.

How are the main ‘primary’ chords of I, IV, and V derived from major and minor keys? We’ll see how they relate to each other, and how other secondary chords can be used to support them to produce a harmonic framework that has the potential to support and enhance those great melodies we want to write!

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