Theory Lesson 2: Major and Minor Scales and Key Signatures

If would be pretty boring we played all music in the same key. But we can rearrange where the half steps are in a scale and get 12 different major keys. (Do you know how many half steps there are in a scale? That’s right, 12!) A major key can be built off of every half step in a scale.

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

You might be wondering why I sharped some notes and made others flat. That’s because you will play something in B♭ a lot more than you will play something in the key of A#. Look at the piano, B♭ and A# are the same note. That means they are enharmonic equivalents: the same note written two different ways.

You know what key you are playing in based on the key signature at the beginning of the music.

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What’s up with all those sharps and flats? They look like they are completely random but they always occur in a certain order. If you have one sharp, it will always be F#. If you have two sharps they will always be F# and C#. The order goes like this:

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

Use the mnemonic “Fat Cats Go Down Allies Eating Birds” to help you remember the order.

For flats, the order is the reverse of what it is for sharps.

B♭ E♭ A♭ D♭ G♭ C♭ F♭

Remember “Bead Go Catch Fish” for flats.

Unfortunately, if you have one sharp, it doesn’t mean you are in the key of F#. But it’s not to difficult to figure out what key you are in. For major keys with sharps, locate the last sharp that is written and go up a half step. That’s your key! So if you have one sharp, then F# is your last and only sharp. Go up a half step=G=key of G major. What if you have four sharps? You know the order will be F# C# G# D#. What’s the last sharp? D#. Now go up a half step to get E major.

For flats, it’s a little different. Find the second to last flat in your key signature and that’s what key you are in. You don’t have to worry about going up half steps. So if you have three flats (B♭ E♭ A♭) The second to last flat is E so you are in the key of E♭ . What if you only have one flat? For now just remember one flat is the Key of F. You’ll understand why when we learn about intervals.

These two tricks work for major keys. We’ll talk about minor keys later.

Major Scales

How do major scales work? Well it all depends on the arrangement of whole and half steps. Start with C major. Can you write half or whole in between each note?

Screenshot-2017-11-7 c major scale whole and half steps at DuckDuckGo.png


This is the order you get. Whole Whole Half Whole Whole Whole Half.

That’s the order of half and whole steps for all major scales which is why major scales sound the same. They have the same relationship between the notes. Try this exercise. Print out some blank sheet music. Notate an E (the first line on the treble staff). Without looking at a scale book and without thinking about your key signature for E, begin writing the scale just by the order of whole and half steps. Now compare your scale to an E major scale in your scale book. If you really  want to give yourself a workout, try doing this for the more complicated scales like A#.

You can number each note in your scale. We call these scale degrees. The numbers above the notes are the scale degrees.  Each note in a scale also has a name which are written below the note in the following picture.

Screenshot-2017-11-7 scale with scale degrees - Google Search.png

Don't worry about remembering the name for each scale degree. The most important ones are tonic, dominant, and the leading tone. Scale degrees and scale names are the same for major and minor keys.

Why do we call the seventh scale degree a leading tone? Because it wants to lead to tonic again. Try playing a scale and stop on the leading tone. You’ll be itching to play the tonic to feel complete. (Legend has it Mozart’s father would play scales in the morning ending on the leading tone. Young Mozart would jump out of bed, run down stairs, and play the tonic. Brilliant idea to get a prodigy up in the morning.)

Minor Key Signatures

You’ve probably recognized that some music sounds happy while other music sounds sad. For the most basic explanation Major=happy and Minor=sad.

For every major key, there is also a minor key that shares the same key signature. So there are 12 minor keys. How do you know if something is major or minor based on the key signature? It’s not always obvious at first since one key signature can have two possible keys (the major key and the minor key). A minor key that shares the same key signature as a major key is called a relative minor.

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Let’s say you have this key signature to the right.

 You’ve played through the song and it sounds sad. Now figure out what minor key you are in. First, determine what the major key would be? Remember for sharps you look at the last sharp written an go up a half step. So we are in the key of D major if we were in major. To determine the relative minor key, go backwards three half steps. I imagine a piano keyboard in my mind to help me count backwards. Three half steps back from D is B so you are in the key of B minor. Going back three half steps works for both sharp and flat keys. To sum it up, to determine a relative minor key determine the major key and go back three half steps to determine what the relative minor key is.

Screenshot-2017-11-6 e major - Google Search.png

Before we move on to what makes up a minor scale, memorize your key signatures. If you see this key signature to the right you want to know immediately it’s E major. Then test yourself on what the relative minor key would be. While it’s important to remember all your key signatures, focus on the ones you will be playing in the most. For now that’s 0-4 sharps or flats. Answers below.


Next we'll talk more about minor scales.

Happy Practicing!