This post is one of a 2-part series of free basic music theory lessons on my blog, musictheoryde-mystified.com. You can see the complete list here. Please feel welcome to make a comment or ask a question.
The Order Of Keys
Look at the list from the last lesson, 11. Introduction To Keys And Key Signatures: Major Keys.
Now that the keys are in key signature order,we can make one more observation:
The order that the keys come in (the order of the root notes of the keys) is the same as the order that the sharps or flats come in, just starting on a different note than the root note, as shown here by the red arrows.
- For sharps keys, the next key is the 5th letter above the current key.
- For flats keys, the pattern is reversed. The next key is the 4th letter above the current key, which is the same as saying it’s the 5th letter below the current key. We call this sequence the Cycle of 5ths (see below).
Sharps Keys
- The sharps keys start with G major (one sharp) and go up 5 letters at a time.
The sharps themselves start with F#, the 7th note of G major. - The latest sharp of a key signature is the 7th note of the scale or one letter below the root note.
Flats Keys
- The flats keys start with F major (one flat) and go down 5 letters at a time.
- The flats themselves start with Bb, the 4th note of F major.
- The latest flat of a key signature is the 4th note of the scale, the 4th letter counting up from the root note.
Why Are Some Notes Missing?
Notice also that some note names aren’t on this list. The list of keys above only goes up to 7 sharps or 7 flats. It could go further, but scales in those keys would have more sharps or flats than notes! We would need to use double sharps or double flats in order to preserve the note naming rule (see 10. How To Find The Notes Of A Scale).
Most notes have two possible names. If the root note isn’t on the list, simply re-spell the note (re-name it with the alternative note name) and it will be there. With the alternate spelling, the same sounding key uses only a few single sharps or flats instead of doubles and is much easier to read. For this reason, keys with more than 7 sharps or flats are seldom used.
For example, G# major has 8 sharps including F double-sharp. The note G# can also be called Ab. Because it’s the root note there is no special reason to use a particular name as long as we have the right pitch. G# can be re-spelled to Ab. Ab major only has 4 flats; Bb, Eb, Ab and Db.
The Cycle (Circle) Of 5ths – The Ultimate Shortcut
The cycle of fifths (aka circle of fifths) is the ultimate shortcut for finding keys and key signatures. It’s just the list of keys we’ve already looked at above, but in condensed form.
Since keys and key signatures follow the same pattern, we don’t need to write them out separately. Here’s how it works:
This is a very long line… We can shorten it a bit by putting the sharps and flats sections on top of each other. The sharps list reads from left to right, the flats list from right to left (see arrows). The green dotted line represents where the sharps and flats themselves start.
To find the key signature of a scale:
- Find the root note. For example, D major is in the sharps row, Db major is in the flats row. F major is in the flats row, F# major is in the sharps row.
- If you can’t find the root note, its key signature has more than 7 sharps or flats. These are seldom used. Re-spell the name and look again.
- The number above (or below) the root note is the number of sharps or flats in the key signature.
- From the start of the row, follow the direction of the arrow until you cross the green dotted line. The first note after that line (the first letter with a sharp or flat) is always the first sharp or flat in the key signature.
- Continue reading the following sharps or flats up to the number that’s written above (or below) the root note.
- On each stave of the piece, write the sharps or flats after the clef, in the order that you found them. Be sure to write them at the standard octave for key signatures, as listed in the previous post, 11. Introduction To Keys and Key Signatures: Major Keys.
Examples
E major
- E major is in the sharps row and has 4 sharps.
- Reading from left to right, the first sharp is always F#.
- Continue counting sharps until there are 4: F#, C#, G#, D#.
Ab major
- Ab major is in the flats row and has 4 flats.
- Reading from right to left, the first flat is always Bb.
- continue counting flats until there are 4: Bb, Eb, Ab, Db.
The first sharp is always F# and the first flat is always Bb. If you remember BCEF, you already know this…
So far we’ve only looked at major keys. For minor keys we could use a similar list as the one above but the sequence would start on A, the minor with no sharps or flats, rather than C. The pattern would be the same but all the numbers would be different.
There is an easier way to do minor keys. We’ll visit that in the next lesson, so for now we’ll just stay with the major keys.
Try These…
Here are a few keys for you to look up in the cycle of 5ths, using either the line version or the circle version below. Find some paper and a pencil and write down the name of each key with the key signature next to it, with the sharps or flats in the correct order. Answers at the end of this post.
- G major
- B major
- Gb major
- Bb major
What’s a 5th?
We haven’t formally looked at interval names yet, that’s for a future post. Essentially, we count the interval (pitch difference) between notes in letters, including the first and last letters of the interval.
From a note to itself, such as C to the same C, is one letter. This interval is called a 1st.
From C to D is 2 letters is a 2nd, from C to E is a 3rd, etc. all the way up to an octave, from C to the next C above (or below) it, the 8th note. Octave means 8th, hence the name “octave”. A 5th is 5 letters, such as from C to G.
Real interval names go a bit further than that but in essence, interval names are based on counting letters.
The cycle of 5ths is so named because the interval from one note to the next in the cycle is a 5th. Reading from left to right, for sharps keys, the cycle goes up in 5ths, while reading from right to left, for flats keys, it goes down in 5ths.
The Circle Game
Many people say Circle of 5ths rather than Cycle of 5ths. This is because, instead of showing the pattern across a page, potentially trailing off each margin forever, it can be shown as a circle. The circle is the most popular way of representing the Cycle of 5ths. It works just the same as the line version we used, with left-to-right (sharps) being clockwise and right-to-left (flats), anticlockwise.
Here’s the circle representation of the cycle of 5ths for major keys.
The circle of 5ths is often shown without the extra sharps/flat: after all, these just follow the same sequence as the root notes. Instead, the key signature is displayed next to each key, as below. This is great as an image on your device but not as clear for committing to memory.
For jotting down quickly on paper from memory, I find the line version easier, but if you have the image to look at, the circle version with key signatures is great. The circle also has the added benefit of being able to show minor keys on the same image. We’ll come back to minor keys in the next post but if you want to have a look, visit The Cycle (circle) Of Fifths.
Know Your Key Signatures
Much of what we’ll learn in the rest of this course is dependent on knowledge of key signatures and the cycle of 5ths. Keys and key signatures are essential concepts in the language of music.
Furthermore, the cycle of 5ths is more than just a list of keys. It also represents the musical relationships between chords within an overall key, possibly the most important topic of all (but that’s for a future post).
TIP: It’s worth learning all the keys and their key signatures, or at least the common keys for your instrument or genre. Start with the major keys. Later I’ll show you a schortcut for minors.
I’m not a fan of unnecessary rules but any language has a basic vocabulary and syntax. Music is no different. Just as we need to learn the symbols for note pitch and duration, the “key” to musical success in almost any genre is to become familiar with keys and key signatures.
A Mnemonic Can Help
In primary schools, the Cycle of 5ths is taught as a mnemonic. Mine was a boring one, Go Down And Enter By Fifths, with a C at each end. I’m sure you can come up with your own… A mnemonic is a good idea because keys are the times tables of music and should be deeply embedded in your mind.
Keys are the times tables of music.
This post is one of a growing series of free basic music theory lessons on my blog, musictheoryde-mystified.com. You can see the complete list here.
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Much of the material in this post, including the custom diagrams, is taken from Music Theory De-mystified, my upcoming music theory reference.
NEXT LESSON: 13. Relative Major And Minor
PART 1 CONTENTS: Basic Music Theory Course Contents
Answers to “Try These”
- G major has 1 sharp, F#
- B major has 5 sharps, F# C# G# D# A#
- Gb major has 6 flats, Bb Eb Ab Db Gb Cb
- Bb major has 2 flats, Bb Eb