Why Keys Are More Connected Than You Think
1. Why Key Signatures Exist
Keys are one of the fundamentals of music and are amongst the first things that many players learn. Typically that’s via the proxy of learning what key signatures look like or by learning scales. However, key signatures play a much more interesting role in demonstrating how music actually works and the web behind the logic of music theory.
Key signatures themselves are typically seen at the start of a piece of music as a “list” of sharps or flats. These tell us which sharps or flats are going to be played throughout the piece of music. However, the first thing to realise is that key signatures come from scales, not the other way around. A key signature is a handy way of showing us what scale a piece of music is using. Once you understand that a key signature is simply the written result of a scale, it becomes much easier to understand.
So when we talk about keys, we are really talking about scales. The term “scale” can just be translated to “a set of notes”, and key signatures show us what set of notes are being used.
But what is the point in having “sets of notes”? Why not just write the sharps/flats next to the notes for every piece?
Well, there are two reasons for this. Firstly, it would be horrendously difficult to read if the page was filled with sharps and flats everywhere. Secondly, scales are not an accident, they are formed using maths, science and a bit of negotiation (due to equal temperament, which is for another day). So having standardised patterns makes learning them and understanding how they relate to each other much more valuab
2. How Keys Are Linked
For the interest of this Monday Music Tips, I’m going to just use major keys as an example. However, the theory holds across minor keys and other more obscure key signatures too.
Firstly, a major key has a particular formula. The relationships between the notes are the same for every major key. That relationship is comprised of gaps of whole steps (W) or half steps (H) and is W–W–H–W–W–W–H. No matter which major key you look at, this will be the relationship between the notes.
However, keys not only hold the same format of notes, but they also relate to each other in a much more specific way. Many people first learn that the key of C major contains no sharps and no flats. This is usually the first key to learn because on the piano that is just the white notes (C D E F G A B). However, we can go through to the 5th note of the scale (5 letters in the alphabet) to find the next sharp key. From C major that would be G major (C D E F G). G major, therefore, contains 1 sharp.
The formulaic nature of keys doesn’t stop there, because it is actually always the 7th note of the scale that is the new sharpened note. In the case of G major, this is the F that becomes an F# (G A B C D E F#).
To demonstrate this further, if we continue 5 notes (G A B C D), we get to D major and the additional sharpened note is the 7th note (D E F# G A B C#).
We can actually also do this for flat keys by going backwards 5 notes from C major. C major, once again, has no sharps or flats (C D E F G A B). If we go down 5 notes in the scale (C B A G F), we get to F major and this contains 1 flat. For flat scales, the additional flattened note is always the 4th note in the scale. So in F major it is the B that becomes a Bb (F G A Bb C D E).
Down 5 notes in the scale from F would be Bb (F E D C Bb), so Bb major has 2 flats and the additional flat is the 4th note in the scale (Bb C D Eb F G A).
This pattern is called the circle of fifths, because we can go up or down 5 notes to get to the nearest related scales (the ones that share a lot of similar notes). Up 5 notes sharpens the scale and down 5 notes flattens the scale. When learning a piece of music, these are also the most likely scales that a key might change to. If we are in C major, G major (1 additional sharp) and F major (1 additional flat) share almost all the same notes as C major and therefore it is easier to travel to these scales and they also share many of the same chords. In contrast, moving from C major (C D E F G A B) to F# major (F# G# A# B C# D# E#) is much harder to stomach, because they only share one note (B).
3. Changing Practice
Key signatures aren’t something that are random or isolated. They are an interwoven network of how music theory really works. They inform the chords and harmony that are being used, the possibility of modulating keys, and which keys are most convenient to modulate to. But they also tell us where our tonal centre is and where tension and release can be found.
Tonal centre is a fancy way of saying “home” and what home feels like. In C major, the note C and a C major chord feel like home. Whereas in G major, a C major chord doesn’t feel like home, it feels like it needs to return to where home actually is, a G major chord.
When we play in a particular key, we are really establishing what home feels like and what landscape we are playing within. But this is not an isolated world. In our two neighbouring fields, we have the possibility of moving to our two neighbouring keys that share a similar yet distinctly different feeling. Beyond that, we can venture to more distant lands with very little in common with our home. Often, the further we travel, the more interesting a perspective we gain before returning home.
The way keys are interconnected and how the science of music shapes what we actually feel when listening to music is a large but informative topic. Keys, key signatures and scales are not simply labels for things you need to learn in music, but a map that shows us what music can actually do and how it does it.
Matt
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