11. Introduction To Keys and Key Signatures: Major Keys

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.

This post and the next two cover two important musical concepts. If you need to read them more than once, please do so. If you have any questions, please post them as a comment. I’ll be happy to answer them.

Scales And Keys: What’s The Difference?

A scale is a list of a series of consecutive notes adding up to an octave, based on and named after its first note, the root note, and its mode (e.g. major or minor).

key is the musical use of the notes of a scale. A piece is said to be in a key, (e.g. C major), when it is largely made up of the notes of the scale (e.g. of C major) and we can hear the tonality of the mode (e.g.major). For more detail, please visit How Can We Tell Which Key We’re In?

I prefer to think of this in reverse priority:

  • A key is music, a scale is a list of notes that music is made from. 
  • A key is the cake, the scale is the ingredient list.
  • A scale is the notes of a key, listed in consecutive pitch order.

Keys and scales have the same name, except if you’re writing or playing a scale you say the word “scale” in the description:

  • “This piece is in C major” means “this piece is in the key of C major”.
  • Else you would say “play the scale of C major” or “play the C major scale”.

In other words, when talking about actual music we say “key”, not “scale”.

Practical Tip: To easily play in a key you need to be familiar with its scale. 

A Scale Has A Key

Since a scale is also a basic melody, a scale itself is in a key. For example, the scale of C major is in the key of C major. 

Unless we’re actually playing scales, we talk in terms of keys rather than scales.

Key Signatures

Apart from C major and A minor, other major or minor keys require some notes that are sharps or flats. So far, we’ve written them in before each note. That’s no big deal if it’s just a scale but in a piece, some of those notes might be used many times. It’s hard work when writing and the music ends up looking cluttered.

Melody in A major without key signature

A key signature uses the space on the stave just after the clef, before the time signature or any notes, to store the sharps or flats of that key for the whole length of the stave. Now they don’t need to be written next to the notes. The music looks cleaner and it’s quicker to write.

Melody in A major with key signature

A key signature is a list of the sharps or flats used in a key.

The note naming rule states that each letter is only used for one note in the scale (7 scale notes, 7 letters), so the scale notes which are NOT in the key signature are naturals.

For example, the key signature of D major is 2 sharps, F# and C#. All the other letters are naturals.

Note: unlike time signatures, key signatures are written at the start of every stave.

The notes of a key can be played at any octave. If that note is a sharp or flat, it’s symbol is written next to the note; at the same octave as the note. In a key signature, however, a sharp or flat is only ever written at one particular octave and it applies to all octaves. It simply tells us that, for a given key, that note is a sharp or flat.

A key signature is a shortcut for writing out a scale. If we start on the root note and play the notes of the key signature, we’re playing the scale for that key.

It’s important to check the key signature, else you may play some wrong notes!

Here are two scales that look the same apart from the key signature. Carefully read the notes as you listen. In these two scales, every note is different because of the key signature!

The Order Of Sharps and Flats

The sharps or flats in the key signature are always written in the same order, regardless of the order in which the notes are played in the scale, and always in the octave shown below.

For sharps, the order is F# C# G# D# A# E# B#. F# is always the first sharp. Each sharp is the 5th letter above the previous sharp.

For flats, it’s the reverse, Bb Eb Ab Db Gb Cb Fb. Bb is always the first flat. Each flat is the 5th letter below (or the 4th letter above) the previous flat.

Don’t worry if you can’t remember all this, we’ll come back to it later…

Let’s look at A major, for example. In the scale, C# comes before F#, but in the key signature, F# appears before C#.


One big advantage to having a set order is that a player only needs to glance at the key signature to know which notes are sharps or flats. If you know the order, you only need to see how many there are.

Here’s the key signature order on the stave in the treble and bass clefs:

Note the octave where the symbols are written. For example, F# is written in the high octave rather than the low octave.

Why This Order?

Let’s say we worked out every major (or minor etc.) scale by counting semitones. If we looked at them all we would notice three things:

  • There are no scales with both sharps and flats.
  • The number of sharps/flats is unique. For example, there is only one major scale with 3 sharps.
  • Sharps and flats are cumulative. Once a sharp (or flat) is used in one scale, all the scales with more sharps (or flats) include that one.

We can reshuffle our list of scales in increasing key signature order. Here’s what the list of major scales looks like. To save space I have listed their key signatures rather than the whole scale:

Note: In the next post we’ll look at key signatures for minor keys as well as some shortcuts for learning key signatures.

Please feel welcome to like, comment or to share this post. If you have any questions, pleased leave them as a comment and I will respond as soon as I can. If you enjoy my posts and would like to be kept up to date, please subscribe.

NEXT LESSON: 12. Major Keys And The Cycle/Circle Of Fifths

PART 1 CONTENTS: Basic Music Theory Course Contents

10. How To Find The Notes Of A Scale

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.

In a hurry? You can scroll down straight to the summary (but you’ll miss all the fun…)

A scale is the combination of a root note and a mode. It’s even named that way. C major means C is the root note and major (Ionian) is the mode. The same for A minor: A is the root note and minor (Aeolian) is the mode.

In 8. What Is A Scale? we saw that a scale is a selection of (typically 7) notes within an octave, and that our sense of tonality depends on knowing which of these notes is the root note. In a piece that has a clear tonality the notes are organised so that the root note (tonic) is highlighted, especially near the beginning and end.

We also discovered that the reason the root note is so important in allowing us to hear the musical character is because typical Western scales have uneven intervals from note to note. Changing the root note effectively changes the pattern, changing the mode and thus its character.

Scales On Different Root Notes

If you know the character of the mode, you can sing a scale in that mode. As long as it’s within your range, you can sing that scale starting on any note (without even knowing what that note is!). As long as you don’t change the mode it will sound the same, just higher or lower. 

The same is true for writing music. You can write a scale on any note. Here’s how it works: 

Let’s look at the the major mode, which naturally starts on C. C major is made up of only the naturals.

We can pick any other note as the root note and build a major scale on that. All we need to do is make sure we stick to the major mode, the pattern of intervals from note to note that matches C major, or else we’ll change its character.

Let’s say we want D major. If we just started on D and used the same notes we would have a different pattern of intervals – a different mode – a different character.

It would sound like this:

This scale has quite a different character to C major.

Instead, we use the same pattern of intervals as C major, write D as the root note and then, working from left to right, count the number of semitones from each note to the next to work out the other notes. This will involve using one or more sharps or flats.

  • The 2nd note should be 2 semitones higher. 2 semitones above D is E. 
  • The 3rd note is 2 semitones higher than E. F is 1 semitone higher than E and G is 3 semitones higher so we want the note in between. This could either be called F# (F+1) or Gb (G-1). What should we call it? We’ll come back to that shortly. We can put in both for now.
  • The 4th note is just 1 semitone further which is plain old G, and so on until the 7th note, 2 semitones above the 6th note, B. Again we have 2 options, C# or Db, and again we’ll write in both for now.
  • And, of course, the 8th note, 1 semitone above the 7th, should be exactly the same as the first, as it is the octave.

OK, time to look at what we’ve got… If we choose Gb for the 3rd note we have Gb AND G but no F, whereas if we call the 3rd note F# we have one F and one G. The same goes for the 7th note: Db uses the same name as the root note but a different sign, whereas C# allows one C and one D.

Now that we’ve worked out the notes in D major, let’s have a listen.

Now compare it to C major. The character should be the same, even though one scale is a little higher than the other…

The Note Naming Rule

For scales, there is one simple rule: the next note in a scale should have the next letter in its name.

Each note in a scale must have its own letter.

There’s a good reason for this: there are 7 note names, 7 notes in a scale and 7 pitch positions per octave on a stave.

Music notation is very visual. We can see the notes climb and descend as the melody itself climbs and descends. As we can see from the two versions of D major below, if two different notes in a scale share the same note name there are two different pitches sharing the same place on the stave and needing constant accidentals (sharps/flats/naturals) to show which is which. There is also one unused position, leaving a gap in the visual that we don’t hear.

Below is D major as notes on a stave showing both sets of note naming options. Try to read the notes while you listen. Which one is more visual (and less cluttered)?

Note: We can make a scale look even less cluttered by using a key signature. We’ll look at key signatures in the next lesson.

How to find the notes of a scale 

Now that we know how to work out what notes we need to write a major scale starting on D instead of C, we can do so for any mode and any root note.

As the most common modes are major and minor, let’s find the notes for some other major and minor scales.

  1. Choose a mode, e.g. major or minor.
  2. Write the note that you want to build the scale on as the 1st note (root note).
  3. Working from left to right, count how many semitones to the next note. Where there are two names for the same note, choose the name using the letter after the previous note.
  4. (safety check: if you’ve added it up right, the 8th note’s name should be exactly the same as the first).

TIP: Learn the patterns that make up the major and minor modes (I think of them as phone numbers).

Major .2.2.1.2.2.2.1.

Minor .2.1.2.2.1.2.2.

Example: D minor

Have a go…

Here’s the answer…

OK, this one’s minor and has a flat. Pure fluke! There is no connection between being major or minor and having sharps or flats.

Try These…

Grab some paper and a pencil and try a few more… Bb major, A major, C minor, F# minor.

Answers at the bottom of this post. Here’s what a blank major and minor look like:

Practical Tip

Pick a major or minor scale that’s easy to play on your instrument, find its notes and doodle around with those notes. Just in one octave will do for a start, then try 2 octaves worth – it’s more fun. As long as you highlight the root note every now and again, for instance by making it long or strong, you should be able to feel the tonality of the mode you’ve chosen, or at least keep coming back to it if the music goes elsewhere. For a bit more on how to highlight the root note, visit How Can We Tell What Key We’re In?

Summary

  • A scale is a combination of a root note and a mode. 
  • The root note is the first note of the mode.
  • A mode is a set of (usually 1 and 2 semitone) intervals from note to note adding up to an octave. The most common modes are major and minor. Of these, only C major and A minor have no sharps or flats.
  • Due to the irregular pattern of intervals from note to note, each mode has a unique musical character.
  • To make a scale on a different root note, choose the mode with the character that you want, e.g. major or minor, and write in the note you want to be the root note.
  • To find names for the other notes, start with the root note and count 1 or 2 semitones to the next note, according to the mode. Write the 2nd note in, count  semitones to the 3rd note and so on, all the way to the octave.
  • Each note of a scale should have its own letter. Work from left to right, using the next letter each time, as you go.

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.

Please feel welcome to like, comment or to share this post. If you have any questions, pleased leave them as a comment and I will respond as soon as I can. If you enjoy my posts and would like to be kept up to date, please subscribe.

NEXT LESSON: 11. Introduction To Keys and Key Signatures: Major Keys

PART 1 CONTENTS: Basic Music Theory Course Contents

Answers

Bb C D Eb F G A Bb

A B C# D E F# G# A

C D Eb F G Ab Bb C

F# G# A B C# D E F#

The Note Naming Rule For Scales And Keys

Each note in a key or scale must have its own letter.

Most Western scales have 7 notes. Including those with a sharp or flat in their name, most notes have two possible names.
We have 7 letters for note names and 7 pitch positions per octave on a stave. It makes sense that each note in a scale has a different letter as it’s name.

(Graphic, dots, D major scale with wrong crossed out and right notes)

Music notation is very visual. We can see the notes climb and descend as the melody itself climbs and descends. As we can see from the two versions of D major below, if two different notes in a scale share the same note name there are two different pitches sharing the same place on the stave and needing constant accidentals (sharps/flats/naturals) to show which is which. There is also one unused position, leaving a gap in the visual that we don’t hear.

(Sib graphics of D major melody, wrong/right notes)

If there are two possible names for a note, always choose the name that’s not used by any other notes in that key or scale.