Understanding the major scale is foundational music theory

At some point in your journey as a guitarist, you’ll need to understand the major scale and some music theory. Just the phrases major scale, and especially music theory, might be enough to send shivers down your spine. I mean, who isn’t afraid of music theory?

What is music theory?

The term music theory defines the collection of the ideas, rules, and relationships that give a formal structure to music. It defines concepts that musicians need common understanding on in order to effectively understand, write, and perform music. It provides this basis for the structure of music while at the same time it allows for creativity in the breaking of the rules and the redefining of the structure.

Now, some people will try to tell you that it’s not important to learn music theory in order to play the guitar. I say nothing could be further from the truth. If you attempt to play at a certain tempo, you’re using music theory. If you attempt to play a chord–or for that matter, even a single note–you’re using music theory.

You cannot play music without using music theory. Period. And the major scale is the best place to start understanding because it plays a fundamental role in pretty much everything musical–at least in modern, western (as in European and American, not as in country western) music.

So, the question isn’t whether or not you’re going to use music theory along your journey as a musician. The question is, “how well are you going to understand the music theory you will use?”

You need to decide how much music theory you want to know

In my opinion, the more music theory you know, the better your chances of becoming an accomplished musician. Up to a point. You can never know too much, but at some point–again, this is just my opinion–you can dig so deeply into the weeds of music theory that it almost ceases to be musical and starts to become clinical.

We all have to decide for ourselves where that threshold is. But as for me, well, I know I haven’t reached it. I’m still learning things about music theory that I feel open new musical doors for me. That give me new ways to see and think about music. So I keep learning what I can.

So, what about you? If you buy the premise that music theory is extremely important to your growth as a musician, then where do you start? No better place to start, I say, than with the major scale.

Start you music theory journey with the major scale

But first, what is a scale?

A scale is simply a way to organize musical notes. In western music (classical, rock, country, folk, and so on) we’ve organized notes into 12 divisions. 12 distinct tones that we call musical notes. Together these 12 notes make up an octave. And within each octave, we can find many scales. And the most important scale is the major scale.

Too much music theory for you already? I know; if you’re new to all of this, it can seem like a lot, but I can simplify it for you. And even though you’re studying to be a guitarist, your best friend for this discussion will be the piano.

The piano: your number one beginning music theory learning tool

When you’re studying music theory for the first time, nothing is more valuable to you than a piano keyboard. The piano enables you to see, feel, and hear music theory more easily than any other way I’ve ever found.

So, find your nearest piano or electronic keyboard. If you don’t have either of those, find an interactive online piano keyboard to use. There are several, like the one at the Online Pianist website.

First, discover the octave

Now, start by playing the white key closest to the middle of the keyboard that sits just to the left of a two black-key pair. Next, play each key to the right of that key–both black and white keys–one after the other. Keep going until you reach the next white key that sits to the left of the next pair of two black keys.

Once you’ve climbed from your starting note all the way up to your ending note, you’ve played an entire octave. You already learned that an octave is divided up into 12 tonal divisions–what music theory calls 12 notes. And, if you count the number of keys you just played, you’ll find 12 keys starting at the first one and ending at the one just to the left of the note you ended on, which is the start of the next octave.

You’ve uncovered the chromatic scale

So, in the process of playing the 12 notes of the octave, you’ve also played your first scale. But you didn’t play the major scale. Instead you played a scale called the chromatic scale, which is simply every note in the octave.

It sounds unstructured. It probably had little meaning to you as you played it. It’s just a confusing succession of notes, each with a slightly different tone than the one before and the one after it.

It’s not all that useful to try and use all 12 notes throughout an entire piece of music. But there will be many times when you use smaller groups of chromatic notes for attention-grabbing passages that can really give your music a flair. That’s for another article.

For now, we need something with a little more structure to help us make sense of all this.

Introducing the note C

The next critical piece of music theory you need to know is the names of the 12 tonal divisions–we’ll use the term notes from here on–within an octave. Looking back at your keyboard, that note you started on–the white key to the left of the pair of two black keys–is the note C. And the note you ended on to the left of the next set of two black keys is also called C.

It’s not too important to know why it’s named C. Besides, I don’t know why. I’m sure somebody does, but remember when we talked about the music theory weeds earlier? That seems like weeds to me, so don’t worry about it. Just accept that this note has the name C.

In fact, every white note to the left of each set of two black keys has the name C. Play two C notes together on your piano. Notice that although they are definitely different, they somehow sound the same too.

Music theory and the science of sound give us a mathematical reason for this similarity, but that’s not super important right now either. What is important is that you understand that every octave has a C note. Just one C note. When you reach the next C note, then you’ve reached the next octave.

And introducing more note names

All of the other notes in any octave have names too. Look at your piano keyboard again. This time, strike the white key that sits between the second and third black keys in the set of three black keys closest to the middle of your keyboard. We call that note A.

Start with that A note and play the next white key higher–that is, to the right on the piano. That’s the note B. The next white note is the C that by now you are already familiar with. The next white note is D, the next E, the next F, the next G. Finally the next white note is the A note that starts the next octave.

So the white keys on a piano are named for the notes they play, and those notes have the names A through G. There is no note called H. Instead, we start over at A again in a new octave.

Music theory is as simple as Do, Re, Mi and the major scale

Now that we know the names of the notes played on the white keys, go back to the note C. Play each white key from the starting C all the way up to the next C. Now you hear something that makes some sense to your ears!

What you hear likely sounds very familiar. You most likely know the tune as Do, Re, Mi, Fa, Sol, La, Ti, Do. That is the major scale! See? Music theory is easy, and you’ve known some all along. You just didn’t know it as music theory because you didn’t know Do, Re, Mi as the major scale!

And notice that the major scale has fewer notes than the chromatic scale. In fact, the major scale has only seven notes instead of the full 12. Remember, in Do, Re, Mi, the first and last notes are both Do. So the second Do starts the new octave.

Know what key you’re in and play with other musicians

To be more precise, you haven’t just played the major scale. You’ve played one of the major scales. There is a major scale for every note in the octave. When you start on a C note and play all the white keys, then you play Do, Re, Mi in the key of C major. You’ve just played the C major scale.

A musical key is really just a group of notes that go together in a specific way. The key that a piece of music is written in defines the character of that music.

Sometime in the future as you continue your musical journey, you’ll play with another musician, and she’ll say, “this song is in C.”

She’s telling you that the song is in the key of C major and thus whatever you play needs to be based upon the C major scale so that you sound good playing together. At that point you’ll be quite glad you know a little bit of music theory!

Where you start determines what key you’re in

Do, Re, Mi defines the major scale, and thus a major key. The note you start the major scale on gives the major scale and the key their names. As we discovered, if you start on the note C and play Do, Re, Mi, you play the major scale in the key of C major.

Since you know that each octave has 12 notes, then you can easily see that each octave has the start of 12 major scales. And each major scale uses exactly seven notes. But not the same seven notes.

Tones and semitones

The C major scale uses all of the seven white keys on the piano. That’s what makes it the easiest key to visualize on the piano. Each other major scale uses different combinations of white and black keys. It will be extremely helpful to know the basic formula for building the major scale in any key so you can always figure it out and know what notes to play in that key.

Start with the note C again and play the C major scale. Notice that as you play from one white key to the next, sometimes you skip a black key and other times there is no black key between two white keys. This helps you visualize the recipe for a major scale. Every major scale, no matter what note you start on.

When you move from one key to the next key, you’re said to have moved a half step, also known as a semitone. So, if you play the note C, then play the black key just to the right of the note C, you’ve moved a half step.

If you play the note C and then skip the black key to play the next white key, you’ve moved a whole step, also called a tone. A whole step from the note C takes you to the note D. As you saw earlier, the white key between the black keys in each set of two black keys is the note D. This shows that it takes a whole step to get from the note C to the note D. Any time you skip a note–that is, a key on the piano–then you’ve gone a whole step, or a full tone.

All you need is a little music theory and a major scale recipe

Following this music theory logic, you can see you need a whole step to get from the note D to the note E. But then you need only a half step to get from E to F. Notice no black key sits between the white E key and the white F key.

Continuing on, it takes a whole step from F to G, a whole step from G to A, a whole step from A to B, and finally a half step from B to the next C. So you can see the the notes of the C major scale are: C, D, E, F, G, A, B.

So, if you visualize all of this together, you see the the recipe of a major scale is Whole Step-Whole Step-Half Step-Whole Step-Whole Step-Whole Step-Half Step. You can notice the pattern more easily with the abbreviations W (for whole step) and H (for half step):

W-W-H-W-W-W-H.

Now you can apply that pattern to figure out the notes of every other major scale. Music theory for the win!

Meet your first sharp

Let’s try it with another key. Start with the note G (the white key between the first two black keys of any three black-key set). Use your new music theory knowledge to follow the major scale recipe and figure out the rest of the notes in the G major scale.

A whole step from G takes you to A. Whole step from A takes you to B. Half step from B takes you to C. Whole step to D, whole step to E, whole step to…whoa! That’s not a white key!

The whole step from E takes you to the first black key in the next group of three black keys. And from that black key, your final move is a half step back to the note G.

You’ve just encountered sharps and flats

Notice that I conveniently neglected to use the name of that black key? And while we’re thinking about it, how come there are 12 notes in an octave, but the names only go from A to G–which is only seven names? Music theory or the major sale must be broken!

Nah, they’re not broken. But those are logical questions, and maybe there’s a music theory reason behind it, but actually I think it’s probably just this way for the sake of convenience.

Instead of trying to assign 12 unique names to each note in the octave, the naming convention developed to give us a manageable seven names to remember. That’s not necessarily music theory based. It’s Gary theory based. Anyway, let’s carry on.

The remaining notes in the octave–represented by the black keys on the piano–have names that are derivatives of those seven note names you already know. You’ve probably heard the terms sharp (the # symbol stands for sharp) and flat (the b symbol stands for flat) before, and these terms define the notes between the named notes.

Naming the sharps and flats

Every black key on the piano represents a note that can be called both a sharp and a flat depending upon which key you’re in. Don’t worry about it. I’ll explain in a bit.

In the case of the G major scale (which you played when you followed the formula starting with the G note), the black key you play sits just a half step above the white F key. This key and the note it plays use the name F sharp (commonly written as F#). Sometimes. Other times the name Gb is appropriate as you’ll see shortly. But in the G major scale, the note is called F#. So, the notes for the G major scale are G, A, B, C, D, E, F#. And the final half step takes you from the F# to the G of the next octave.

No matter which key, it’s still Do, Re, Mi

And did you notice that this G major scale still sounds like Do, Re, Mi? In fact, every major scale sounds like Do, Re, Mi.

You can now use the formula for the major scale, to construct the major scale in any key. Start on the white keys and work out the major scale that starts on each one.

Meet your first flat

As you make your way up the keyboard starting on different white keys, sooner or later you’ll run into another little music theory quirk: a major scale must use each of the note names (either alone or modified by a sharp or flat) exactly once. So, you can’t have, say, an A and an A# in the same major scale.

But you already learned that a black key can be called either a sharp or a flat note. So which is it? How do you know?

Let’s take a look at an example: the key of F. Start on an F key on your piano and apply the major scale formula. F whole step to G, G whole step to A. So far so good. But from A the formula calls for a half step, so move up to the next black key.

That note sits between A and B, so what do you call it? An A sharp or a B flat? As I said, music theory dictates that it can’t be called A# because you already have an A note in your scale. Therefore, you have to call it a B flat (commonly written as Bb).

So, to finish the F major scale, whole step from Bb to C, whole from C to D, whole from D to E, and then the half step back to the F in the next octave.

Enough about the piano–let’s play guitar!

One last thing. We’ve done a lot of talking about the piano here. But we’re guitar players, right? Rest assured that everything you learned here–all the music theory and every major scale–works exactly the same on guitar as it does on piano. It’s just much, much easier to visualize it on piano.

But you can work out any major scale on the guitar too. The music theory is identical. For instance, start on the third fret of the low E string. As you know from my article A Simple Pattern Can Help You Learn the Notes on a Guitar, that’s the note G.

Now follow the recipe for the major scale. While you don’t have black and white frets, you can still easily identify half steps and whole steps. When you move one fret higher, that’s a half step. Two frets higher is a whole step.

So, the G major scale on the E string starts at fret three. It then moves a whole step to A at fret five and another whole to B at fret seven. The first half step takes you to C at fret 8. Then a whole to D at fret 10, whole to E at fret 12, whole to F# at fret 14. The final half step takes you back to G at fret 15–one octave higher than where you started.

If you’re able to play that scale on your guitar while a friend plays the same scale on the piano, you’ll hear that they sound exactly the same. Well, assuming you are both properly in tune, and excepting the fact that one sounds like a guitar and the other a piano…but I guess you know what I mean!

You no longer need to fear music theory

See? You already know a bunch of music theory! And you now understand the concept of octaves, scales, half steps, whole steps, sharps, flats, and the major scale. From here, you can really start understanding music and your instrument.

Who said music theory was scary?

Conclusion

Music theory has a bad reputation as something to be feared. But you simply can’t play music without understanding some music theory. The only question is, how well do you want to understand it?

You can use the piano to visualize music theory, and it soon becomes less daunting.

No musical scale plays a more important role than the major scale. 12 notes make up an octave. Seven of those notes make the major scale. There are 12 major scales and which one you play depends upon which note you start on.

You can also play the major scale on guitar in any key.